Harðardóttir is an Icelandic patronymic surname, literally meaning "daughter of Hörður". It may refer to:
- Eygló Harðardóttir (born 1972), Icelandic politician
- Manuela Ósk Harðardóttir (born 1983), Icelandic beauty queen and model
- Oddný Guðbjörg Harðardóttir (born 1957), Icelandic politician
Similar name for a son is Harðarson.