Born in Sola, Rogaland, Norway, Sebulonsen started playing football for hometown club Sola FK as a 13-year-old.[1][4] After progressing through the youth teams of the club, he made his senior debut on 24 September 2016, aged 16, in a Norwegian Second Division match against Florø.[5] On 1 July 2017, he scored his first goal at senior level, contributing to a 4–1 away victory against Express in the Norwegian Third Division.[6] At the end of his tenure at the club, Sebulonsen had scored 18 goals in 67 appearances for Sola.[1]
Viking
On 12 December 2019, Sebulonsen signed a two-year contract with Eliteserien club Viking.[7] On 21 June 2020, he made his league debut for the club in a 3–0 loss against Brann, replacing Johnny Furdal in the 68th minute.[8] On 29 November, he scored his first goal for the club, opening the score with a header in the 20th minute, helping Viking to a comfortable 4–1 victory against Start.[9][10]
On 11 May 2021, his contract was extended for two more years, keeping him at Viking until December 2023.[11] The next day, he was loaned out to fellow Eliteserien club Mjøndalen.[12] There he made four appearances, putting in impressive performances, including one against his parent club Viking, where he provided an assist.[13] On 9 June 2021, Viking recalled him from his loan.[14] He scored 11 goals in 67 appearances during his time at Viking.[1]