Ritter is a surname of German origin, and may refer to:

• Alexander Ritter (1833–1896), German composer, violinist, and conductor
• Alison Ritter, Australian drug policy academic
• Alois Ritter (1897–1966), President of the Landtag of Liechtenstein
• August Ritter (civil engineer) (1826–1908), German civil engineer
• August Gottfried Ritter (1811–1885), German romantic composer and organist

• Bill Ritter (born 1956), American politician and former Governor of Colorado
• Bill Ritter (journalist) (born 1950), American news anchor in New York City
• Bruce Ritter (1927–1999), American Roman Catholic priest, founder of Covenant House
• Burwell C. Ritter (1810–1880), American politician, Congressman from Kentucky 1865–1867

• Carl Ritter (1779–1859), German geographer
• Christian Ritter (1645–50 – after 1725), German composer and organist
• Christian Ritter (footballer) (born 1984), German football player

• Dominik Ritter (born 1989), Swiss football player
• Donald L. Ritter (born 1940), American politician, Congressman from Pennsylvania 1980–1993

• Erika Ritter (born 1948), Canadian playwright and humorist

• Floyd Ritter (1870–1943), Major League Baseball catcher 1890
• Frédéric Louis Ritter (1834–1891), German-American composer and author
• Friedrich Ritter (1898–1989), German botanist, expert on cacti

• Gerhard Ritter (1888–1967), German conservative historian
• Gerhard A. Ritter (1929–2015), German historian
• Gretchen Ritter, American academic administrator

• Halsted L. Ritter (1868–1951), American jurist impeached and removed from office in 1936
• Heinrich Ritter (1791–1869), German philosopher
• Henry Ritter (1816–1853), Canadian genre painter

• J. Alfred Ritter (died 1892), American politician from Maryland
• Jason Ritter (born 1980), American actor, son of John Ritter
• Jeannie Ritter (born 1958), former First Lady of Colorado, US; wife of former Governor Bill Ritter
• Johann Christian Ritter (1755–1810), first printer in South Africa
• Johann Wilhelm Ritter (1776–1810), German chemist and physicist
• Johannes Ritter (born 1995), Danish footballer
• John Ritter (congressman) (1779–1851), American politician, Congressman from Pennsylvania 1843–1847
• John Ritter (1948–2003), American actor, son of Tex Ritter, father of Jason Ritter
• John H. Ritter (born 1951), American young-adult baseball novelist
• John Steele Ritter, American pianist, long-term collaborator of French flautist Jean-Pierre Rampal
• Joseph Ritter (1892–1967), American Cardinal, Archbishop of Saint Louis 1946–1967
• Josh Ritter (born 1976), American singer-songwriter

• Krysten Ritter (born 1981), American actress

• Lawrence Ritter (1922–2004), American baseball writer
• Lorenz Ritter (1832–1921), German painter
• Lou Ritter (1925–2010), American politician, mayor of Jacksonville, Florida 1965–1967
• Louise Ritter (born 1958), American track and field athlete, Olympic gold medalist

• Matthew Ritter, American politician
• Maya Ritter (born 1993), Canadian actress
• Michael Ritter (born 1957), Deputy Prime Minister of Liechtenstein

• Nikolaus Ritter (1899–1974), German Intelligence Officer

• Ole Ritter (born 1941), Danish professional cyclist

• Paul Ritter (1966–2021), British stage and screen actor
• Paul Ritter (architect) (1925–2010), Australian architect, artist and author
• Paul Ritter (painter) (1829–1907), German architectural painter and etcher
• Paul Ritter (diplomat) (1865–1921), Swiss ambassador to the United States
• Preston Ritter (1949–2015), American rock drummer

• Rex Ritter, lead guitarist for the American band Jessamine 1994–1998
• Robert Ritter (1901 – c. 1951), German psychologist whose work led to the genocide of the Roma people in Nazi Germany
• Karlheinz Ritter (1929–2008), President of the Landtag of Liechtenstein

• Scott Ritter (born 1961), chief United Nations weapons inspector in Iraq 1991–1998
• Sylvester Ritter (1952–1998), ring name Junkyard Dog, American professional wrestler

• Tex Ritter (1905–1974), American singer and actor, father of John Ritter
• Thelma Ritter (1902–1969), American actress
• Tyson Ritter (born 1984), American musician, lead singer and bassist for The All-American Rejects

• William Ritter (1867–1955), Swiss writer
• William Emerson Ritter (1856–1944), American biologist
• William M. Ritter (1864–1952), American businessman

• Mary Ritter Beard (1876–1958), American historian and campaigner for woman's suffrage
• F. Ritter Shumway (1906–1992), major figure in American figure skating
• Albert Ritter Conti v. Cedassamare (1887–1967), Italian-American character actor
• Pavao Ritter Vitezović (1652–1713), Croatian writer, historian, linguist, and publisher
• Stephen Geoffreys (born 1964), American actor who used the screen name Sam Ritter in pornographic films

• Donald & Deborah Ritter, characters from Marvel Comics
• Philip Ritter, a doctor played by Paul Henreid in the 1952 film Stolen Face
• Rein Weiss Ritter, a robot in the Super Robot Wars series
• Rhonda Ritter, a character in the 1982 film Grease 2
• Robert (Bob) Ritter, fictional CIA Deputy Director of Operations in the Tom Clancy novel Clear and Present Danger (1989)
  • The same character, played by Henry Czerny, in the 1994 film adaptation of the novel
• Weiss Ritter, a robot in the Super Robot Wars series
• Alwin Ritter, a fictional character in the anime Gundam SEED DESTINY
• Thomas, Jacob, and Lily Ritter, characters from the 2013 video game State of Decay

• Ritter (titular name)
• Rebecca Ritters (born 1984), Australian actress