Juan Martín Fernández Lobbe (born 19 November 1981 in Buenos Aires) is an Argentine rugby union footballer.

He played for Toulon in the French Top 14, having moved from Sale Sharks in England's Guinness Premiership.

He was a part of the Pumas team that defeated Wales at home in a two Test series, scoring a try in one game.

He played in every game en route to the semi-final which they lost to the eventual champions South Africa.

However Fernández Lobbe retained the captaincy in the absence of Felipe Contepomi and defeated England in front of their home crowd in 2009.