| Ernest Simoni | Albanian Roman Catholic cardi… | 1928 |
| Paul Simonon | English musician (Bass guitar… | 1955 |
| Henry Calvert Simons | American economist | 1899–1946 |
| Menno Simons | Dutch theologian, founder of … | 1496–1561 |
| Paullina Simons | Russian writer | 1963 |
| Margarita Simonyan | Russian propagandist | 1980 |
| Simple plan (band) | | |
| Alan Simpson | American politician | 1931 |
| Anne Simpson | Canadian poet | 1956 |
| Ashlee Simpson | American singer, actress, dan… | 1984 |
| Brooks D. Simpson | American historian | 1957 |
| George Gaylord Simpson | American paleontologist | 1902–1984 |
| Jessica Simpson | American singer-songwriter an… | 1980 |
| Louis Simpson | Jamaican poet | 1923–2012 |
| Matthew Simpson | American bishop and academic | 1811–1884 |
| Mona Simpson | American novelist | 1957 |
| Brian Sims | American politician | 1978 |
| George Robert Sims | English journalist, poet, dra… | 1847–1922 |
| Frank Sinatra | American singer and film actor | 1915–1998 |
| Marion Sinclair | Australian music teacher and … | 1896–1988 |
| Upton Sinclair | American novelist, writer, jo… | 1878–1968 |
| Simon Sinek | British/American author and m… | 1973 |
| Isaac Bashevis Singer | Polish-born Jewish-American a… | 1902–1991 |
| Israel Singer | American Jewish activist | 1942 |
| Margaret Singer | clinical psychology | 1921–2003 |
| Michael Singer | American landscape architect | 1945 |
| Peter Singer | Australian philosopher | 1946 |
| Ajaib Singh | Sant Ajaib Singh (11 Septembe… | 1926–1997 |
| Bhagat Singh | Indian revolutionary | 1907–1931 |
| Charan Singh | prime minister of India | 1902–1987 |
| Darshan Singh | | 1932 |
| Guru Govind Singh | The tenth and last human Guru… | 1666–1708 |
| Harbhajan Singh | Indian cricketer | 1980 |
| Jagseer Singh | Paralympic long jumper | 1987 |
| Jaswant Singh | Indian politician and retired… | 1938–2020 |
| Jeev Milkha Singh | professional golfer | 1971 |
| Kanwer Singh | Canadian YouTube Star, Rapper… | 1981 |
| Khushwant Singh | Indian novelist and journalist | 1915–2014 |
| Manmohan Singh | 13th Prime Minister of India | 1932 |
| Milkha Singh | Indian track and field athlete | 1935 |
| Nalini Singh | | |
| Pratap Singh | Fijian politician | |
| Rajendra Singh | formerly Professor of Physics… | 1921–2003 |
| Rajnath Singh | Indian politician | 1951 |
| Ranjit Singh | founder of Sikh Empire (early… | 1780–1839 |
| Simon Singh | British author | 1964 |
| Surendra Pratap Singh | Indian journalist | 1948–1997 |
| Tavleen Singh | Indian journalist | 1950 |
| Vijay R. Singh | Fijian politician | 1931–2006 |
| V. P. Singh | Indian politician | 1931–2008 |
| Zail Singh | Indian politician and former … | 1916–1994 |
| Philip Sington | British writer | 1962 |
| Gary Sinise | American actor | 1955 |
| Alfred Percy Sinnett | English writer and Theosophist | 1840–1921 |
| Diogenes of Sinope | ancient Greek philosopher, on… | -404–-322 BC |
| Marcion of Sinope | Christian theologian | 85–160 |
| Wee Ka Siong | A Malaysian engineer and poli… | 1968 |
| Juha Sipilä | Finnish businessman and polit… | 1961 |
| James W. Sire | American writer | 1933–2018 |
| Ahmad Sirhindi | Indian philosopher | 1564–1624 |
| Maithripala Sirisena | Sri Lankan politician, 7th Pr… | 1951 |
| Marvi Sirmed | Pakistani human rights courte… | 1972 |
| Jean Sirmond | French poet | 1589–1649 |
| Publilio Siro | Latin writer | |
| Aaron Siskind | American photographer | 1903–1991 |
| Sofía Sisniega | Mexican actress | 1989 |
| Ali Sistani | Iranian-Iraqi Muslim scholar | 1930 |
| Curtis Sittenfeld | Novelist, short story writer | 1975 |
| Willem de Sitter | Dutch cosmologist | 1872–1934 |
| Edith Sitwell | British poet | 1887–1964 |
| Osbert Sitwell | British baronet | 1892–1969 |
| Swami Sivananda | Indian philosopher | 1887–1963 |
| Nikki Sixx | American musician | 1958 |
| Ted Sizer | American education reformer | 1932–2009 |
| Fryderyk Skarbek | Polish noble | 1792–1866 |
| Bill Skarsgård | Swedish actor | 1990 |
| Skee-Lo | American rapper | 1973 |
| John Skelton | English poet | 1460–1529 |
| Red Skelton | American comedian | 1913–1997 |
| Matt Skiba | American musician | 1976 |
| Robert Skidelsky | Economist and author | 1939 |
| B.F. Skinner | American behaviorist | 1904–1990 |
| Dennis Skinner | British politician | 1932 |
| Kiron Skinner | American writer | 1961 |
| Quentin Skinner | British historian | 1940 |
| Otto Skorzeny | Austrian SS-Standartenführer … | 1908–1975 |
| Mark Skousen | American economist, investmen… | 1947 |
| W. Cleon Skousen | ex FBI agent, conservative Un… | 1913–2006 |
| Obert Skye | American writer | 1970 |
| John C. Slater | American physicist | 1900–1976 |
| Lauren Slater | American psychologist | 1963 |
| Nigel Slater | English food writer, journali… | 1958 |
| Karin Slaughter | US-american crime writer | 1971 |
| Frank Slay | American record producer | 1930–2017 |
| William Sleator | Young adult science fiction n… | 1945–2011 |
| William Henry Sleeman | British colonial administrator | 1788–1856 |
| Leo Slezak | Austrian opera tenor | 1873–1946 |
| Walter Slezak | actor | 1902–1983 |
| Grace Slick | American musician, writer and… | 1939 |
| William Slim, 1st Viscount Slim | former Governor-General of Au… | 1891–1970 |
