In politics and the military:

• Thomas Ryan (congressman), (1837–1914), Congressional representative from Kansas
• Thomas Ryan (Irish Army Officer), (1893-1980) I.R.A Commander and Lt. Col. Irish Defence Forces
• Thomas Ryan (Quebec politician), (1804–1889), businessman and Senator from Quebec
• Thomas Ryan (Victorian politician) (1870-1943), Australian politician - Member for Essendon in the Victorian Legislative Assembly
• T. J. Ryan (1876–1921), Australian politician - Premier of Queensland, Australia (1915–1919), also New South Wales Parliament member (1921)
• Thomas Jefferson Ryan (1890–1968), Congressional representative from New York
• Thomas J. Ryan (admiral) (1901-1970), American admiral and Medal of Honor recipient

In business:

• Thomas Ryan (businessman), executive at CVS Corporation
• Thomas Fortune Ryan (1851–1928), U.S. businessman
• Thomas V. Ryan, Entrepreneur In Residence at Bessemer Venture Partners
• Tony Ryan, (1936-2007), born Thomas Anthony Ryan, the Irish founder of Ryanair

In sports and gaming:

• Tommy Ryan, (1870-1948), American barenuckle boxer
• Tom Ryan (gamer), (1986- ), professional computer gamer
• Tom Ryan (lacrosse), professional lacrosse coach and player
• Tommy Ryan (rugby league), Australian rugby league footballer

In books, music and television:

• Thomas Ryan (musician) (1827–1903), Irish-American musician
• Thomas J. Ryan (author), (1942 - ), author
• Tom Ryan (Primeval), a fictional character from the TV series Primeval
• Tom Ryan (The Unit), a fictional character from the CBS drama The Unit

In other usage:

• Thomas F. Ryan, (1872–1961), Inventor of five-pin bowling
• Tom Ryan (disc jockey), a Detroit-based disc jockey who one went locally by the alter ego Count Scary.