He is on the books of Lyn Oslo and wears shirt number 10. His main role on the pitch is Forward. He measures 188cm in height and weighs 85kg. His stronger foot is Right. His estimated market valuation currently stands at 200K €.

His latest transfer saw him join Lyn Oslo from FK Arendal via on 2024-01-31.

During the Norwegian 1.Divisjon 2025 campaign, Mathias Johansen made 30 appearances, scoring 5 goals and adding 8 assists. He averaged 0.2 goals per match from 0 shots, with 0 on target.