Vasilije Kostov

On 3 January 2025, Kostov was promoted to the first team from Red Star Belgrade U19 team. On 16 January, Kostov made his debut for the first team in a friendly match in Antalya against OFK Beograd. On 26 February, Kostov was first included in the club's main team's roster for the Serbian SuperLiga match against Železničar Pančevo, but did not play. On 6 April, Kostov made his debut in the Serbian SuperLiga championship, coming on as a substitute in the match against OFK Beograd. On 2 October, Kostov scored his first UEFA Europa League goal at the age of 17 years, 4 months and 21 days in the league phase match against Porto – becoming the youngest scorer in the European competition of Red Star. On 31 October, Kostov extended his contract with Red Star until 2028. On 22 February 2026, Kostov scored his first goal in the Eternal derby at the age of 17 years, 9 months and 11 days in the Serbian SuperLiga match against Partizan Belgrade – becoming the youngest scorer in the Eternal derby.

On 11 October 2025, Kostov made his debut for the Serbia national team at the age of 17 years and 5 months in the 2026 FIFA World Cup qualification – UEFA Group K match against Albania.

Kostov first played football at the age of six for ŠF Royal FC, and in 2016, after two and a half years arrived at the Red Star Belgrade youth school and went through all the younger categories. Kostov also stood out for his phenomenal shot from distance, scoring a goal in the youth eternal derby against Partizan, which ended in a victory for Red Star. Despite being one of the youngest footballers on the field, Kostov took on the responsibility and with a goal from the penalty spot, an attractive panenka. On 14 November 2024, Kostov extended his contract with Red Star until 2027.

On 14 October 2025, Kostov was named for The Guardian's Next Generation 2025.