Iorwerth (Welsh pronunciation: [ˈjɔrwɛrθ]) is a Welsh name, composed of two elements: iôr meaning 'lord' and berth meaning 'fair', 'fine', or 'handsome'.^[1] (Both morphemes are somewhat archaic in Modern Welsh.) The name has historically been associated with the name Edward,^[1] although the names do not have a common origin and neither name is a translation of the other.

Bearers of the name include:

• Iorwerth Beli (fl. second half of the 14th century), Welsh language poet
• Iorwerth ap Bleddyn (1053–1111), prince of Powys in eastern Wales
• Iorwerth Drwyndwn (1145–1174), son of Owain Gwynedd, king of Gwynedd
• Iorwerth (bishop of St David's) (fl. 1215)
• Thomas Iorwerth Ellis OBE (1899–1970), Welsh classicist and author
• Iorwerth Evans (1906–1985), rugby union footballer of the 1930s
• Iorwerth Hirflawdd, ancestor of various medieval rulers in mid Wales
• Iorwerth Isaac (1911–1966), Welsh dual-code international rugby flanker
• Iorwerth Jones (1903–1983), Welsh rugby union and professional rugby league footballer
• Iorwerth Peate (1901–1982), Welsh poet and scholar
• Iorwerth Thomas (1895–1966), Welsh Labour Party politician
• Llywelyn ap Iorwerth (1172–1240), Llywelyn the Great, de facto ruler over most of Wales
• Rhun ap Iorwerth, Plaid Cymru Member of the Senedd for Ynys Môn

• Iolo
• Iori (disambiguation)