Gilbert Roland, Luis Antonio Damaso de Alonzo, Actor (Mexico, 1905-1994).

Sir Humphrey Rolleston, Doctor; Humphrey Davy Rolleston (1862-1944).

Jules Romains, Author; Louis Henri Jean Farigoule (Saint-Julien-Chapteuil, Haute-Loire, France 26 August 1885 - 14 August 1972).

Ruth Roman, Actor; Norma Roman (Lynn, Massachusetts 23 December 1924 - 9 September 1999).

Michael Romanoff, Impostor/restaurant owner, Harry F. Gerguson (presumed but unproven) (Russia, 1892-1971).

Lina Romay, Actor; Rosa Maria Almirall (Barcelona 23 June 1954).

Lil' Romeo, Rapper; Percy Romeo Miller Junior (New Orleans
20 November 1989).

Cesar Romero, Actor, Cesar Julio Romero, Jr. (New York, USA, 1907-94) Joker in 1960s "Batman".

Mickey Rooney, Actor  Joe Yule Jnr. (USA 1920).

Anna Eleanor Roosevelt, Wife of president Franklin D. Roosevelt; Anna Eleanor Roosevelt (New York City
11 October 1884 - 7 November 1962). Married and maiden name were the same, as she was her husband's second cousin.

Franklin D. Roosevelt, 32nd President of the United States; Franklin Delano Roosevelt (New York, 12 June 1893 - 12 April 1945).

Teddy Roosevelt Jr., Soldier and businessman; Theodore Roosevelt Jr. (Oyster Bay, New York 13 September 1887 - 12 July 1944).

Axl Rose, Vocalist and co-founder of Guns N' Roses; William Bruce Rose Bailey (Lafayette, Indiana 6 February 1962). Born William Bruce Rose; adopted by his stepfather so his name changed to Bailey.

Billy Rose, Songwriter; William Samuel Rosenberg (New York City 6 September 1899 - 10 February 1966).

John Roselli, Gangster; Filippo Sacco, aka Don Giovanni, aka John F. Stewart (Esteria, Italy, July 4, 1905 - July 1976). Nicknamed Handsome Johnny.

Ethel Rosenberg, Spy; née Ethel Greenglass (New York City 28 September 1915 - 19 June 1953). "It was a queer, sultry summer, the summer they executed the Rosenbergs" - Victoria Lucas, The Bell Jar.

Ida Rosenthal, Dressmaker; Ida Kaganovich ( 9 January 1886 - 29 March 1973). Credited as the developer of the modern brassiere. She Americanized her Kaganovich to Cohen.

Annie Ross, Actor, Annabelle Short, (England 1930).

Betsy Ross, Seamstress née Elizabeth Griscom, later Mrs. John Ross, Mrs. Joseph Ashburn, and finally Mrs. John Claypoole (Philadelphia, Pennsylvania 1 January 1752 - 30 January 1836). She is thought to be the maker of the first American flag.

Diana Ross, Singer; Diane Earle Ross (Detroit, Michigan 26 March 1944).

Joe E. Ross Actor; Joseph Roszawikz Manhatten, New York 15 March 1914 - 13 August 1982

Marion Ross, Actor; Marian Ross (Albert Lea, Minnesota 25 October 1928).

Dante Gabriel Rossetti, Poet and painter; Gabriel Charles Dante Rossetti (London 12 May 1828 - 9 April 1882).

Portia De Rossi, Actor; Amanda Lee Rogers (Melbourne, Australia 31 January 1973). Some sources insist on Amanda Marie Rogers.

Judith Rossner, Writer; Judith Perelman (New York 1 March 1935 - 9 August 2005).

John Rostill, Bass guitarist; John Henry Rostill, (Kings Norton, Birmingham, England 16 June 1942 - 26 November 1973).

Mark Rothko, Painter, Marcus Rothkovitch, (Russia, 1903-1970).

Lillian Roth, Lillian Rutstein, Actor (USA, 1910-1980).

Philip Roth, Author; Philip Milton Roth (Newark, New Jersey 19 March 1933).

Mark Rothko, Expressionist artist; Marcus Rothkovich (Dvinsk, Russia 25 September 1903 - 25 February 1970).

Johnny Rotten, Singer; John Joseph Lydon (Holloway, London 31 January 1956).

Mickey Rourke, Actor, boxer; Philip Andre Rourke Jr. (Schenectady, New York 16 July 1956).

Dan Rowan, Comedian; Daniel Hale Rowan (Beggs, Oklahoma 2 July 1922 - 22 September 1987). See also Dick Martin.

Tiny Rowland, "Businessman"  Roland Walter Fuhrhop (British, 1917 -98).

Gena Rowlands, Actor, Virginia Catherine Rowlands, (USA, 1930).

Patsy Rowlands, Actor; Patricia Rowlands (London 19 January 1934 - 22 January 2005).

J.K.Rowling, Author; Joanne Rowling (Chipping Sodbury, England 31 July 1965). Ms Rowling added Kathleen much later, feeling the lack of a middle name.

Roy [of Siegfried and Roy], Illusionist; Roy Uwe Ludwig Horn (Nordenham, Germany 3 October 1944).

Sir Henry Royce, Engineer; Frederick Henry Royce (Alwalton in Northamptonshire 27 March 1863 - 12 April 1933).

Pete Rozelle, Commissioner of the National Football League (NFL) 1960 - 1989; Alvin Ray Rozelle (South Gate, California 1 March 1926 - 6 December 1996).