She has been a member of the Icelandic parliament, the Alþingi, since 2013. Silja Dögg Gunnarsdóttir represents the Framsóknarflokkurinn party (the liberal progress party) for which she has been the vice-chair of the party group in the Alþingi since 2016. In the Nordic Council, Silja Dögg Gunnarsdóttir represents the Centre Group.
In the Alþingi, Silja Dögg Gunnarsdóttir sits on the economy and trade committee and the foreign affairs committee, to name just two, and has been a member of the Icelandic delegation to the Nordic Council since 2016. She has been the chair of the delegation since 2017.
Silja Dögg Gunnarsdóttir was elected as president for 2020 at the Nordic Council Session in Stockholm in October 2019.