She became Mayor of Reykjavík in 1994 when she led a coalition of four political parties called Reykjavíkurlistinn, winning the elections.
Þórólfur Árnason took over as the mayor of Reykjavík on 1 February 2003 after the Left Greens and the Progressive Party had demanded that Ingibjörg Sólrún Gísladóttir, which was mayor next before Þórólfur, would either resign, or decide not to pursue a career in national politics.