On the local level he was a member of Skien municipality council from 1991 to 1995. During the same term he was also a member of Telemark county council.
After the 2011 Norwegian local elections the local centre-right alliance was dissolved, and Riis-Johansen became Telemark's county mayor of a new centre-left coalition.[1]
Riis-Johansen served as both the first and last county mayor of Vestfold og Telemark between 2020 and 2023, when the county was split into the new and re-established counties of Telemark and Vestfold. He was succeeded by Anne Strømøy in Vestfold on 18 October 2023, followed by Sven Tore Løkslid in Telemark on 23 October 2023.
References
^Holmquist, Tone (22 September 2011). "Høyre vinner fylkesduellen". Kommunal Rapport (in Norwegian). p. 10.