Dafydd is a Welsh masculine given name, related to David, and more rarely a surname. People so named include:

Given name

Medieval era

Ordered chronologically

• Dafydd ab Owain Gwynedd (c. 1145 – 1203), Prince of Gwynedd
• Dafydd ap Gruffydd (1238–1283), Prince of Wales
  • Dafydd Goch, said to be the illegitimate son of Dafydd ap Gruffydd
• Dafydd ap Gwilym (c. 1315/1320–c. 1350/1370), Welsh poet
• Dafydd ap Llywelyn (1215–1246), Prince of Gwynedd and first Prince of Wales
  • Dafydd ap Dafydd ap Llywelyn (born between 1240 and 1246-?), illegitimate son of Dafydd ap Llywelyn
• Dafydd Bach ap Madog Wladaidd (fl. 1340–1390), Welsh poet
• Dafydd Benfras (fl. 1230–1260), Welsh court poet
• Dafydd Ddu o Hiraddug (died 1371), Welsh poet, grammarian and cleric
• Dafydd Gam (1380–1415), Welsh soldier and nobleman who died at the Battle of Agincourt
• Dafydd ab Ieuan or David Holbache (died 1422/3), Welsh politician
• Dafydd Gorlech (c. 1410 – c. 1490), Welsh poet
• Dafydd Llwyd ap Llywelyn ap Gruffudd (Dafydd Llwyd o Fathafarn) (fl. c.1400–c.1490), Welsh poet
• Dafydd Nanmor (fl. 1450–1490), Welsh poet
• Dafydd ab Edmwnd (fl. c. 1450 – 1497), Welsh poet

Modern era

• Dafydd Trystan Davies (born 1974), Welsh academic and politician
• Dafydd Elis-Thomas (born 1946), Welsh politician
• Dafydd Hewitt (born 1985), Welsh retired rugby union player
• Dafydd Howells (born 1995), Wales rugby union player
• Dafydd ab Hugh (born 1960), American science fiction author born David Friedman
• Dafydd Ieuan (born 1969), Welsh musician and producer
• Dafydd Ifans (born 1949), Welsh novelist and translator
• Dafydd James (born 1975), Wales retired rugby union player
• David Richards (Dafydd Ionawr) (1751–1827), Welsh poet
• Dafydd Iwan (born 1943), Welsh folk singer and politician
• Dafydd Jones (disambiguation)
• David Edward Lewis (1866–1941), Welsh businessman and philanthropist
• Dafydd Llywelyn (1939–2013), Welsh composer, pianist, conductor and teacher
• Dafydd Elystan Morgan, Baron Elystan-Morgan (1932–2021), Welsh politician
• Dafydd Rogers (born 1969), West End and Broadway theatre producer
• Dafydd Rowlands (1931–2001), Welsh Congregational minister, lecturer, writer and poet
• Dafydd Stephens (1942–2012), Welsh audiological physician and professor
• Dafydd Wigley (born 1943), Welsh politician
• Dafydd Williams (born 1954), Canadian physician and retired astronaut

Surname

• Catrin Dafydd, Welsh writer, winner of the Crown at the 2018 National Eisteddfod
• Einir Dafydd, Welsh singer who won the third series of the television talent show Wawffactor and the 2007 Cân i Gymru competition
• Fflur Dafydd (born 1978), Welsh novelist, singer-songwriter and musician
• Guto Dafydd (born c. 1990), Welsh writer
• Myrddin ap Dafydd (born 1956), Welsh editor and prifardd (Chief Bard)