|Full name||John Stefan Medina Ramírez|
|Date of birth||14 June 1992|
|Place of birth||Envigado, Colombia|
|Height||1.79 m (5 ft 10 1⁄2 in)|
|* Senior club appearances and goals counted for the domestic league only and correct as of 27 May 2013.
† Appearances (Goals).
John Stefan Medina Ramírez (born 14 June 1992) is a Colombian footballer who currently plays for Monterrey in the Liga MX. Initially he debuted for Atlético Nacional as a centre back. As time progressed, he has shown to be comfortable playing as a right back and on some occasions as a winger. His clean style of play and similar physical attributes has led him to be considered the heir of Colombian legend Andrés Escobar.
A youth product of Nacional's academy, Medina played as a starter in the youth squad for one season before making his senior debut in 2011. Eventually, he gained a spot in the senior squad in 2012 after making occasional appearances. He was given the number 2 shirt in tribute to the late Andrés Escobar who also wore the same shirt, mostly because he's managed to avoid committing fouls as a defender by making good challenges. He has been liken to the late Nacional legend because of this.
Medina finished his career with Nacional in 2014, winning 6 domestic trophies over the course of 4 seasons.
On 30 May 2014 the Mexican club Monterrey confirmed the signing of Stefan Medina for the fee of $4,200,000. He made his debut against Leones Negros, stating that while he was pleased with his debut, he still needs more time to fully adapt to Mexican football.
Following his debut, Medina has been the target of harassment by many Colombian supporters by social media. This is given by his first two matches against Uruguay and Chile, where he failed to make a difference for the national team in which Colombia gave up 2 goals in a 0-2 loss and 3 goals in a 3-3 draw respectively. Although others have defended him (such as teammates and Colombian supporters) over the fact that he simply lacked international experience, and was rushed in by the team's coach, Jose Pekerman where he should not have been even started in both games.
- Atlético Nacional
- Categoría Primera A (4): 2011-I, 2013-I, 2013-II, 2014-I
- Copa Colombia (2): 2012, 2013
- Superliga Colombiana: 2012