Sigríður Ásta Olgeirsdóttir is an Icelandic actress, singer and theatre maker. She has a BA in acting from Copenhagen International School of Performing Arts. She studied classical singing at The Reykjavík Academy of Singing and Vocal Arts and Universität für Musik und darstellende Kunst Wien. Furthermore she has studied privately over longer periods with international singing professors and coaches such as; prof. André Orlowicz, prof. Helene Karusso og Janet Haney

Sigríður has worked professionally as a performer in Iceland as well as internationally since 2019. In 2023 Sigríður wrote, produced and performed the monologue Hidden in Tjarnarbíó Theatre, directed by Halldóra Rósa Björnsdóttir. The play was also performed on RVK Fringe Festival and won the Baltic Nordic Fringe Network Award and will tour Scandinavia and the Baltic countries next spring. She played in Je m’apelle Steinn written and directed by Lucas Rastoll, produced by La Reine Mer Theatre. This same year she wrote a play to commissioned by Kammeróperan that was performed on Big Bang! childrens festival.

She performed in Moetïvi Caravan, a devised theatre piece performed inside a transformed caravan. The production, directed by Greta Clough, was a part of Reykjavík Arts Festival 2022.
In the summer of 2022 Sigríður wrote and performed a concert-theatre fusion about the Icelandic settler, Guðríður Þorbjarnardóttir, commissioned by the piano duet Is Nord. The performance toured churches in Iceland.

Sigríður is co-founder of Flækja slf, a theatre group that has written and produced children's theater since 2019.

Sigríður teaches acting and singing for various institutes as well as taking on projects as a director. Sigríður teaches at the Reykjavík Academy of Singing and Vocal Arts.