- January 2 – José Antonio Remón Cantera, president of Panama, is assassinated at a race track in Panama City.
- January 3 – José Ramón Guizado becomes president of Panama.
- January 5 – The Strömsund Bridge in Sweden is completed, being the first significant cable-stayed bridge of the modern era.
- January 7 – Marian Anderson is the first African-American singer to perform at the Metropolitan Opera in New York City.
- January 17 – USS Nautilus, the first nuclear-powered submarine, puts to sea for the first time, from Groton, Connecticut.
- January 18–January 20 – Battle of Yijiangshan Islands: The Chinese Communist People's Liberation Army seizes the islands from the Republic of China (Taiwan).
- January 22 – In the United States, The Pentagon announces a plan to develop intercontinental ballistic missiles (ICBMs), armed with nuclear weapons.
- January 23 – The Sutton Coldfield rail crash kills 17, near Birmingham, England.
- January 25 – The Presidium of the Supreme Soviet of the Soviet Union announces the end of the war between the USSR and Germany, which began during World War II in 1941.
- January 28 – The United States Congress authorizes President Dwight D. Eisenhower to use force to protect Formosa from the People's Republic of China.
- February 9 – Apartheid in South Africa: 60,000 non-white residents of the Sophiatown suburb of Johannesburg are forcibly evicted.
- February 10 – The United States Seventh Fleet helps the Republic of China evacuate the Chinese Nationalist army and residents from the Tachen Islands to Taiwan.
- February 12 – U.S. President Dwight D. Eisenhower sends the first U.S. advisors to South Vietnam.
- February 14 – WFLA-TV signs on the air in Tampa/St. Petersburg, Florida.
- February 16 – Nearly 100 die in a fire at a home for the elderly in Yokohama, Japan.
- February 19 – The Southeast Asia Treaty Organization (SEATO) is established, at a meeting in Bangkok.
- February 22 – In Chicago's Democratic primary, Mayor Martin H. Kennelly loses to the head of the Cook County Democratic Party, Richard J. Daley, 364,839 to 264,077.
- February 24 – The Baghdad Pact (CENTO), originally known as Middle East Treaty Organization (METO), is signed between Iraq and Turkey.
- March 2
- Claudette Colvin, a 15-year-old African-American girl, refuses to give up her seat on a bus in Montgomery, Alabama, to a white woman after the driver demands it. She is carried off the bus backwards, while being kicked, handcuffed and harassed on the way to the police station. She becomes a plaintiff in Browder v. Gayle (1956), which rules bus segregation to be unconstitutional.
- Serious floods occur in Australia.
- March 5
- WBBJ-TV signs on the air in Jackson, Tennessee, with WDXI as its initial call-letters, to expand American commercial television in mostly rural areas.
- Elvis Presley makes his television debut on "Louisiana Hayride", carried by KSLA-TV Shreveport (although audio recordings exists, there is no known video footage of this appearance).
- March 7 – The Broadway musical version of Peter Pan, which had opened in 1954 starring Mary Martin, is presented on television for the first time by NBC-TV, with its original cast, as an installment of Producers' Showcase. It is also the first time that a stage musical is presented in its entirety on TV, almost exactly as it was performed on stage. This program gains the largest viewership of a TV special up to this time, and it becomes one of the first great TV family musical classics.
- March 17 – Richard Riot in Montreal: 6,000 people protest the suspension of French Canadian ice hockey star Maurice Richard of the Montreal Canadiens by the National Hockey League, following a violent incident during a match.
- March 19 – KXTV signs on the air in Sacramento, California, as the 100th commercial television station in the United States.
- March 20 – The movie adaptation of Evan Hunter's novel Blackboard Jungle premieres in the United States, featuring the famous single "Rock Around the Clock" by Bill Haley & His Comets. Teenagers jump from their seats to dance to the song.
- May 5 – West Germany becomes a sovereign country, recognized by important Western countries such as France, the United Kingdom, Canada and the United States.
- May 6 – The Western European Union Charter becomes effective.
- May 7 – Newcastle United F.C. in England win the Football League First Division title for the fourth time; they will not win it again within the following 60 years.
- May 9
- May 11 – Japanese National Railways' ferry Shiun Maru sinks after collision with sister ship Uko Maru, in thick fog off Takamatsu, Shikoku, in the Seto Inland Sea of Japan; 166 passengers (many children) and 2 crew members are killed. This event is influential in plans to construct the Akashi Kaikyō Bridge (built 1986-98).
- May 12 – New York's Third Avenue Elevated runs its last train between Chatham Square in Manhattan and East 149th Street in the Bronx, thus ending elevated train service in Manhattan.
- May 14 – Warrington win the British Rugby League Championship title for the third time; they will not win it again within the following 60 years.
- May 14 – Eight Communist Bloc countries, including the Soviet Union, sign a mutual defence treaty in Warsaw, Poland, that is called the Warsaw Pact (it will be dissolved in 1991).
- May 15 – The Austrian State Treaty, which restores Austria's national sovereignty, is concluded between the 4 occupying powers following World War II (the United Kingdom, the United States, the Soviet Union, and France) and Austria, setting it up as a neutral country.
- May 25 – Joe Brown and George Band are the first to attain the summit of Kangchenjunga in the Himalayas, as part of a British team led by Charles Evans.
- July 7 – The New Zealand Special Air Service is formed.
- July 13 – Ruth Ellis is hanged for murder in London, becoming the last woman ever to be executed in the United Kingdom.
- July 17 – The Disneyland theme park opens in Anaheim, California, an event broadcast on the American Broadcasting Company television network.
- July 18
- The first nuclear-generated electrical power is sold commercially, partially powering the town of Arco, Idaho.
- Illinois Governor William Stratton signs the Loyalty Oath Act, passed by the state legislature, which mandates all public employees take a loyalty oath to Illinois and the United States, or lose their jobs.
- The first Geneva Summit meeting between the United States, the Soviet Union, the United Kingdom, and France begins. It ends on July 23.
- July 22 – In Long Beach, California, U.S.A., Hillevi Rombin of Sweden is crowned Miss Universe.
- July 27 – El Al Flight 402 from Vienna (Austria) to Tel Aviv, via Istanbul, is shot down over Bulgaria. All 58 passengers and crewmen aboard the Lockheed Constellation are killed.
- July 28 – The first Interlingua Congress is held in Tours, France, leading to the foundation of the Union Mundial pro Interlingua.
- October 2 – Alfred Hitchcock Presents debuts on the CBS TV network in the United States.
- October 3 – The Mickey Mouse Club debuts on the ABC-TV network in the United States.
- October 4 – The Reverend Sun Myung Moon is released from prison in Seoul, South Korea.
- October 5 – Disneyland Hotel opens to the public in Anaheim, California.
- October 11 – 70-mm film for projection is introduced, with the theatrical release of Rodgers and Hammerstein's musical film, Oklahoma!.
- October 14 – The Organization of Central American States secretariat is inaugurated.
- October 20 – Disc jockey Bill Randle of WERE (Cleveland) is the key presenter of a concert at Brooklyn High School (Ohio), featuring Pat Boone and Bill Haley & His Comets, and opening with Elvis Presley (Elvis's first filmed performance), for a documentary on Randle titled The Pied Piper of Cleveland.
- October 26
- October 27 – The film Rebel Without a Cause, starring James Dean, is released in the United States.
- October 29 – Soviet battleship Novorossiysk explodes at moorings in Sevastopol Bay, killing 608 (the Soviet Union's worst naval disaster to date).
- December 1 – In Montgomery, Alabama, Rosa Parks refuses to obey bus driver James F. Blake's order that she give up her seat to make room for a white passenger, and is arrested, leading to the Montgomery bus boycott.
- December 4 – The International Federation of Blood Donor Organizations is founded in Luxembourg.
- December 5
- December 9 – Adnan Menderes of DP forms the new government of Turkey (22nd government).
- December 10 – 1955 Australian federal election: Robert Menzies' Liberal/Country Coalition Government is re-elected with a substantially increased majority, defeating the Labor Party led by H. V. Evatt. This election comes in the immediate aftermath of the devastating split in the Labor Party, which leads to the formation of the Democratic Labor Party. The DLP will preference against Labor, and keep the Coalition in office until 1972.
- December 14
- The Tappan Zee Bridge over the Hudson River, in New York State, opens to traffic.
- Albania, Austria, Bulgaria, Cambodia, Finland, Hungary, Ireland, Italy, Jordan, Laos, Libya, Nepal, Portugal, Romania, Spain, and Sri Lanka join the United Nations simultaneously, after several years of moratorium on admitting new members that began during the Korean War.
- December 20 – Cardiff is declared by the British Government as the capital of Wales.
- December 22 – American cytogeneticist Joe Hin Tjio discovers the correct number of human chromosomes, forty-six.
- December 31
- World population: 2,755,823,000
- Africa: 246,746,000
- Asia: 1,541,947,000
- Europe: 575,184,000
- South America: 190,797,000
- North America: 186,884,000
- Oceania: 14,265,000
- January 1
- January 2 – Vivien Savage, French singer
- January 4 – Mark Hollis, English musician (d. 2019)
- January 5
- January 6 – Rowan Atkinson, English comedian and actor
- January 9 – J. K. Simmons, American actor
- January 10 – Michael Schenker, German guitarist (Scorpions, UFO, Michael Schenker Group)
- January 13
- January 14 – Kim Renders, Canadian writer, director, actor and designer (d. 2018)
- January 15
- January 17
- January 18
- January 19
- January 20
- January 21 – Jeff Koons, American artist
- January 22
- January 23 – Ruth Haring, American chess player (d. 2018)
- January 25 – Petra Gerster, German television presenter and newscaster
- January 26
- January 27
- January 28
- January 29
- February 1 – Hans Werner Olm, German television and film comedian
- February 2 – Leszek Engelking, Polish poet, writer and translator
- February 3 – Kirsty Wark, Scottish television presenter
- February 6
- February 7 – Miguel Ferrer, American actor (d. 2017)
- February 8
- February 9
- February 10
- February 12 – Ai Satō, Japanese voice actress
- February 13 – Akiko Yano, Japanese singer-songwriter
- February 14 – Mitsuhisa Taguchi, Japanese footballer (d.2019)
- February 15
- February 17 – Mo Yan, Chinese writer
- February 19 – Jeff Daniels, American actor
- February 21 – Kelsey Grammer, American actor and comedian
- February 22 – David Axelrod, American political analyst
- February 23
- February 24
- February 28 – Gilbert Gottfried, American actor and comedian
- March 1
- March 2
- March 3 – Kent Derricott, Canadian TV personality in Japan
- March 4 – Dominique Pinon, French actor
- March 5
- March 6
- March 7
- March 8 – Don Ashby, Canadian ice hockey player (d. 1981)
- March 9
- March 10
- March 11 – Nina Hagen, German pop singer
- March 13
- March 15
- March 16
- March 17 – Gary Sinise, American actor, producer and director
- March 18
- March 19
- March 20
- March 21
- March 22
- March 23 – Moses Malone, American basketball player (d. 2015)
- March 24
- March 26 – Danny Arndt, Canadian ice hockey player
- March 27 – Mariano Rajoy, Prime Minister of Spain
- March 28
- March 29
- March 30
- March 31 – Angus Young, lead guitarist of Australian rock group AC/DC
- April 1 – Ockie Oosthuizen, South African rugby union player (d. 2019)
- April 2 – Sirindhorn, Princess Royal of Thailand
- April 3
- April 5
- April 6 – Michael Rooker, American actor
- April 7
- April 8
- April 9 – Kate Heyhoe, American food writer
- April 11 – Kevin Brady, American politician
- April 13
- April 15 – Dodi Fayed, Egyptian businessman (d. 1997)
- April 16
- April 17
- April 18 – Bobby Castillo, American baseball player (d. 2014)
- April 20 – Rotimi Fani-Kayode, Nigerian-born British photographer (d. 1989)
- April 21
- April 23
- April 24
- April 25
- April 26 – Chen Daoming, Chinese actor
- April 27
- James Risen, American Pulitzer Prize-winning investigative reporter and author
- Eric Schmidt, American software engineer and businessman, CEO of Google (2001-2011)
- Jing Yidan, Chinese former television host
- April 28 – Eddie Jobson, English musician
- April 29
- April 30 – Zlatko Topčić, Bosnian writer and screenwriter
- June 1 – Chiyonofuji Mitsugu, Japanese sumo wrestler (58th Yokozuna grand champion) (d. 2016)
- June 2 – Dana Carvey, American actor and comedian
- June 5 – Fernando Borrego Linares, Cuban singer and songwriter (aka Polo Montañez)
- June 6
- June 7
- June 8
- June 10
- June 11 – Yuriy Sedykh, Ukrainian hammer thrower
- June 14
- Kim Lankford, American actress, businesswoman and horse wrangler
- Paul O'Grady (also known as "Lily Savage"), English talk show host and comedian
- June 15
- June 16 – Laurie Metcalf, American actress
- June 18 – Sandy Allen, American, world's tallest woman (d. 2008)
- June 20 – Tor Nørretranders, Danish author
- June 21
- June 22
- June 23
- June 24
- June 25
- June 26
- June 27
- June 28 – Shirley Cheriton, British actress
- June 29
- June 30
- August 2
- August 3
- August 4
- August 6
- August 7
- August 8 – Diddú (Sigrún Hjálmtýsdóttir), Icelandic soprano and songwriter
- August 9 – Doug Williams, American football quarterback
- August 10 – Mel Tiangco, Filipina television anchor, journalist and humanitarian
- August 12
- August 13 – Daryl, American magician (d. 2017)
- August 14 – Gillian Taylforth, English television actress
- August 17 – Richard Hilton, American businessman
- August 19
- August 20 – Agnes Chan, Hong Kong-born TV personality in Japan
- August 22
- August 23 – David Learner, British actor, Stephen M.Papuzek
- August 24 – Mike Huckabee, American politician, Governor and 2008 Presidential candidate
- August 25 – John McGeoch, Scottish musician (d. 2004)
- August 27
- August 30
- August 31 – Edwin Moses, American athlete
- September 1
- September 2
- September 4
- September 6 – Raymond Benson, American author
- September 7 – Efim Zelmanov, Russian mathematician
- September 9
- September 12 – Peter Scolari, American actor and comedian
- September 15
- September 16
- September 17
- September 18 – Bob Papenbrook, American voice actor (d. 2006)
- September 19 – Richard Burmer, American composer, sound designer and musician (d. 2006)
- September 21 – Richard Hieb, American astronaut
- September 24 – Shinbo Nomura, Japanese manga artist
- September 25
- September 28 – Stéphane Dion, Canadian politician
- September 29 – Joe Donnelly, American politician
- September 30
- October 1 – P. B. Abdul Razak, Indian politician (d. 2018)
- October 2 – Philip Oakey, English synth-pop singer-songwriter (The Human League)
- October 3 – Tommy Wiseau, American film director and actor, known for the 2003 "dark comedy" The Room
- October 5
- October 7
- Clinton Bennett, British scholar of religions, specialist in the study of Islam
- Yo-Yo Ma, French-born Chinese American cellist
- October 8
- October 12 – Pat DiNizio, American singer-songwriter (The Smithereens) (d. 2017)
- October 13 – Sergei Shepelev, Russian ice hockey player
- October 15
- October 17 – Tyrone Mitchell, American murderer (d. 1984)
- October 18
- October 19
- October 20
- October 21
- October 24
- October 25 – Glynis Barber, South African-born British actress
- October 28
- October 29
- October 30 – Jeremy Black, British historian
- October 31 – Eduardo V. Manalo, 3rd Executive Minister (Tagapamahalang Pangkalahatan) of the Iglesia ni Cristo (Church of Christ)
- November 1 – Joe Arroyo, Colombian salsa and tropical music singer (d. 2011)
- November 2 – Chris Burnett, American saxophone player, composer, veteran of US military jazz bands and band leader
- November 3
- November 4
- November 5
- November 6 – Maria Shriver, American television journalist, host; former First Lady of California
- November 7
- November 9 – Karen Dotrice, Guernsey-born child actress
- November 10 – Roland Emmerich, German film director
- November 11 – Jigme Singye Wangchuck, King of Bhutan
- November 13 – Whoopi Goldberg, African-American actress and comedian
- November 14 – Koichi Nakano, Japanese bicycle racer
- November 17
- November 19 – Dianne de Leeuw, Dutch figure skater
- November 20 – Ray Ozzie, American computer programmer
- November 21
- November 22 – George Alagiah, Ceylonese-born British newsreader, journalist and television news presenter
- November 23
- November 24
- November 25 – Bruno Tonioli, film, music video and theater choreographer
- November 26 – Tracy Hickman, American author
- November 27 – Bill Nye, American science presenter and public television host
- November 28 – Alessandro Altobelli, Italian football player
- November 29 – Howie Mandel, Canadian actor and game show host
- November 30
- December 3
- December 4 – Maurizio Bianchi, Italian musician
- December 7 – Priscilla Barnes, American actress
- December 8
- December 9 – Asashio Tarō IV, Japanese sumo wrestler
- December 12 – Gianna Angelopoulos-Daskalaki, Greek politician and businesswoman
- December 13 – Manohar Parrikar, Indian politician (d. 2019)
- December 14 – Hervé Guibert, French writer and photographer (d. 1991)
- December 16
- December 17 – Brad Davis, American basketball player
- December 21
- December 23
- December 24
- December 27 – Barbara Olson, American television commentator (d. 2001)
- December 28 – Liu Xiaobo, Chinese literary critic and human rights activist, Nobel Peace Prize laureate (d. 2017)
- December 31 – Jim Tracy, American baseball player and manager
- March 3 – Katharine Drexel, American Roman Catholic foundress and saint (b. 1858)
- March 8 – William C. deMille, American screenwriter and director (b. 1878)
- March 9 – Matthew Henson, American explorer (b. 1866)
- March 11 – Sir Alexander Fleming, Scottish scientist, recipient of the Nobel Prize in Physiology or Medicine (b. 1881)
- March 12 – Charlie Parker, American saxophonist (b. 1920)
- March 16 – Nicolas de Staël, Russian painter (b. 1914)
- March 19 – Mihály Károlyi, 1st President of Hungary and 20th Prime Minister of Hungary (b. 1875)
- March 23 – Arthur Bernardes, 12th President of Brazil (b. 1875)
- March 24 – John W. Davis, American politician, diplomat, and lawyer (b. 1873)
- November 1 – Dale Carnegie, American writer and lecturer (b. 1888)
- November 4 – Cy Young, American baseball player (Cleveland Spiders) and a member of the MLB Hall of Fame (b. 1867)
- November 5 – Maurice Utrillo, French artist (b. 1883)
- November 7 – Tom Powers, American actor (b. 1890)
- November 12 – Alfréd Hajós, Hungarian swimmer and architect (b. 1878)
- November 14 – Robert E. Sherwood, American playwright (b. 1896)
- November 15 – Lloyd Bacon, American actor and director (b. 1889)
- November 17 – Helmuth Weidling, German general (b. 1891)
- November 22 – Shemp Howard, American actor and comedian (The Three Stooges) (b. 1895)
- November 27 – Arthur Honegger, French-born Swiss composer (b. 1892)