Cornelis Henricus Johannes "Kees" de Boer (born 13 May 2000) is a Dutch professional footballer who plays as a midfielder for Italian Serie C Group B club Ternana.

He made his professional debut for Swansea's first team in a 3–1 home win over Northampton Town at Liberty Stadium in the EFL Cup.

[5] De Boer joined VVV-Venlo, who had suffered relegation alongside ADO, on 6 July 2021, signing a two-year contract with an option for an additional season.

[8] On 15 September 2023, De Boer officially joined Italian side Ternana on a free transfer, signing a one-year contract with the club, with an option for another season.

On 10 February 2015, he made his debut for the Netherlands U15 in a 1–1 friendly draw against Serbia U15, providing the assist for Jurgen Ekkelenkamp's equalizer from his corner kick.