Jason Guida is a former American professional mixed martial artist who last competed for Bellator. A professional competitor from 2003 until 2014, he also fought for EliteXC, the WEC, KSW, Adrenaline MMA and World Extreme Fighting. Jason is the older brother of Ultimate Fighting Championship veteran Clay Guida.

Konfrontacja Sztuk Walki better known by its initials KSW, is widely considered to be the premiere mixed martial arts organization in Poland and one of the leading in Europe.