He is on the books of Vikingur Reykjavik Women and wears shirt number 27. His main role on the pitch is Forward.

During the Iceland Besta-deild kvenna 2025 campaign, Thordis sigfusdottir made 15 appearances, scoring 1 goals and adding 0 assists. He averaged 0.1 goals per match from 0 shots, with 0 on target.