Bjarnadóttir is an Icelandic surname. Notable people with the surname include:
Guðbjörg Jóna Bjarnadóttir (born 2001), Icelandic sprinter Hafdís Bjarnadóttir (born 1977), Icelandic composer Kristín Bjarnadóttir (1812–1891), Icelandic politician Kristín Ýr Bjarnadóttir (born 1984), Icelandic footballer Sóllilja Bjarnadóttir (born 1995), Icelandic basketball player Valgerður Bjarnadóttir (born 1950), Icelandic politician
See also Jorunn Bjarnadottir, character