Kristian Fredrik Malt Arnstad (born 7 September 2003) is a Norwegian professional footballer who plays as a midfielder for Danish Superliga club AGF and the Norway national team.
A youth product of Heming, Arnstad signed with Anderlecht on 15 September 2019. Arnstad made his professional debut with Anderlecht in a 3-0 Belgian First Division A loss to Club Brugge KV on 4 October 2020.
On 31 August 2024 the Danish Superliga club AGF confirmed that Arnstad joined the club on a deal until June 2029.