| Raegan Butcher | American actor and singer | 1969 |
| Dawn Butler | British politician | 1969 |
| Geezer Butler | English musician, bassist and… | 1949 |
| Josephine Butler | British feminist | 1828–1906 |
| Judith Butler | American philosopher and gend… | 1956 |
| Nicholas Murray Butler | American philosopher, diploma… | 1862–1947 |
| Octavia E. Butler | American science fiction writ… | 1947–2006 |
| Rab Butler | British politician | 1902–1982 |
| Samuel Butler | novelist | 1835–1902 |
| Smedley D. Butler | United States Marine Corps Ge… | 1881–1940 |
| William Allen Butler | American lawyer | 1825–1902 |
| Tom Butler-Bowdon | Australian writer | 1967 |
| Elizabeth Butler-Sloss | English judge | 1933 |
| Sikandar Butshikan | | |
| Hassan Butt | British-Pakistani activist | 1980 |
| Munir Butt | British diplomat | 1940–2015 |
| Herbert Butterfield | British historian | 1900–1979 |
| Pete Buttigieg | American politician | 1982 |
| Mary Butts | Novelist | 1890–1937 |
| Earl Butz | American government official | 1909–2008 |
| Charles Buxton | English brewer, philanthropis… | 1823–1871 |
| Tony Buzan | British psychologist | 1942–2019 |
| Lewis Buzbee | American writer | 1957 |
| Dino Buzzati | Italian writer | 1906–1972 |
| Winnie Byanyima | Ugandan aeronautical engineer… | 1959 |
| Betsy Byars | American children's writer | 1928 |
| A. S. Byatt | English fiction writer and cr… | 1936 |
| Max Bygraves | Singer, comedian, actor | 1922–2012 |
| Vasil Bykaŭ | Belarusian writer | 1924–2003 |
| Witter Bynner | American author | 1881–1968 |
| Andrew Bynum | American basketball player | 1987 |
| Richard Evelyn Byrd | Medal of Honor recipient and … | 1888–1957 |
| William Byrd | British composer | 1543–1623 |
| David Byrne | Scottish alternative rock mus… | 1952 |
| Ed Byrne | Irish comedian | 1972 |
| Gabriel Byrne | Irish actor, film director, f… | 1950 |
| John Byrne | American author and artist of… | 1950 |
| Rhonda Byrne | Australian writer and producer | 1951 |
| Robert Byrne | American chess player and wri… | 1928–2013 |
| Michael J. Byrnes | American Roman Catholic archb… | 1958 |
| John Byrom | Poet, inventor of a shorthand… | 1692–1763 |
| George Gordon Byron | English poet and a leading fi… | 1788–1824 |
| Yoo Byung-eun | South Korean religious leader… | 1941–2014 |
