Viljami Kari Veikko Sinisalo (born 11 October 2001) is a Finnish professional footballer who plays as a goalkeeper for Scottish Premiership club Celtic, and the Finland national team.

Sinisalo spent his youth career with HyPS, HJK and Honka,[4] and made his senior league debut for Espoo in third-tier level Kakkonen in June 2017, aged only 15.

[18][19] On 16 July 2024, Sinisalo signed for Scottish Premiership club Celtic on a five-year deal for an undisclosed fee,[20] reported to be £1 million.

[25] On 14 September 2022, Sinisalo was called up in the Finland senior squad, previous to their UEFA Nations League matches against Romania and Montenegro.

[27] On 12 January 2023, Sinisalo made his debut in the senior Finland national football team in a 1–0 friendly defeat to Estonia.

[28] Sinisalo made his competitive international debut on 20 November 2023, in a UEFA Euro 2024 qualifying match against San Marino.