Youri Marion A. Tielemans (born 7 May 1997) is a Belgian professional footballer who plays as a midfielder for Premier League club Aston Villa and the Belgium national team.

On 28 July 2013, he made his first-team debut in the opening round of the Belgian Pro League season against Lokeren, replacing injured Sacha Kljestan after 25 minutes of a 2–3 home loss.

[7] On 2 October 2013, he became the youngest Belgian player to play in the UEFA Champions League, starting in a match against Olympiacos at the age of 16 years and 148 days.

[13] He made his competitive debut on 29 July in the Trophée des Champions at the Grand Stade de Tanger, playing the full 90 minutes in the 2–1 loss to Paris Saint-Germain and assisting Djibril Sidibé's opening goal.

[19] On 31 January 2019, Tielemans joined Premier League club Leicester City on loan until the end of the season, with Adrien Silva going the other way in a swap deal.

[27] On 10 June 2023, Premier League club Aston Villa announced that they had reached an agreement to sign Tielemans on a free transfer, upon the expiry of his Leicester City contract on 1 July.

[28] He made his debut on 12 August in the season opener, a 5–1 loss at Newcastle United, in which he replaced the injured Leon Bailey at half time.

[31] He finally made his senior international debut on 9 November 2016, in a 1–1 friendly away draw to rival Netherlands, replacing Steven Defour in the 82nd minute.

[39][40] Tielemans began as a holding midfielder, but was moved by Anderlecht manager Besnik Hasi to a more attacking role, where he scored long-range goals and was compared to Frank Lampard and Axel Witsel.

[7] A 2015 profile by Sky Sports noted his versatility as a defensive or attacking midfielder, concluding that his pace, passing and shot power suited the latter role better.