Magnus Nordengen Knudsen (born 15 June 2001) is a Norwegian professional footballer who plays as a midfielder for Danish Superliga club AGF.
On 23 December 2021, Rostov announced the signing of Knudsen from Lillestrøm with a 4.5-year contract. On 24 March 2022, he returned to Lillestrøm on loan until 30 June 2022. On 7 July 2022, the loan was extended until 30 June 2023.
On 29 June 2023, Knudsen moved to AGF in Denmark on a one-year deal.
On 14 June 2024, he signed a contract with Holstein Kiel in Germany.
On 26 January 2026, Knudsen returned to AGF and signed a four-and-a-half-year contract.