O'Dempsey: Last Name Origin and Family Crest

O'Dempsey is best understood together with Dempsey: both are Irish spellings of one family name. In origin, the name means “Descendant of Díomasach ("proud")”.

• The O' in front of the name is a particle that was often added to Dempsey in records.
• Other spellings include Dempsy and Dempster.

Family crest and blazon

Arms linked to Dempsey and its spellings were granted to individual families; our heraldry team traces which line they belonged to. Get the complete O'Dempsey report, with a museum-style coat of arms.