Edgar Alejandro Sosa Medina ( born August 23, 1979 in Mexico City, Mexico) is a Mexican professional boxer.

Sosa suffered losses in the early part of his career, the first one came against another future Mexican light flyweight champion Ulises Solis. He faced off against Solis in a rematch in 2003 but lost once again. Sosa would then score fourteen straight victories including a win over former two time minimum weight champion Noel Arambulet.

On April 14, 2007, Sosa won the WBC light flyweight title by besting former champion Brian Viloria by unanimous decision. Sosa has defended his title eight times since then. The most recent one, a 4th round technical knockout victory over Porsawan Popramook on April 4, 2009. On Novermber 21, 2009, Sosa lost his title to Rodel Mayol. In the second round, Sosa was badly hurt by a headbutt from Mayol which caused him to fall to the canvas and sustain a cut above his cheek. The referee ruled the headbutt as an intentional foul and deducted a point from mayol. When the action resumed, Sosa was dropped and the referee waved it off moments later. Sosa, who was later hospitalized due to a fractured cheekbone sustained from the headbutt, filed a protest with the WBC to have the decision changed to a "no contest".