Riordan
Riordan or O'Riordan is a family name for the following people:
- Bill Riordan (1908–1973), Australian politician
- Cait O'Riordan (* 1965), Irish bass player
- Claire O'Riordan (* 1994), Irish football player
- Daniel J. Riordan (1870–1923), American politician
- Derek Riordan (born 1983), Scottish football player
- Dolores O'Riordan (1971-2018), Irish singer and songwriter
- James Riordan (1936–2012), English Soviet scientist, sports scientist and writer
- John R. Riordan (* 1943), Canadian biochemist
- John Riordan (banker) , American banker
- John Riordan (mathematician) (1903–1988), American mathematician
- John Riordan (poker player) , American poker player
- John O'Riordan CSSp (1924-2016), Irish clergyman, Roman Catholic Bishop of Kenema
- John R. Riordan (* 1943), Canadian biochemist
- Mike Riordan (* 1945), American basketball player
- Nick O'Riordan (* 1953), British geotechnician
- Patrick William Riordan (1841–1914), Archbishop of San Francisco
- Richard Riordan (* 1930), American politician
- Rick Riordan (* 1964), American writer
- Sean O'Riordan (1916–1998), Irish religious and moral theologian
