31+ Download images of Jason Alexander. He is well known for his portrayal of george costanza in . Jason alexander on being cast in the seinfeld chronicles, the pilot to seinfeld. Jason alexander (born jay scott greenspan on september 23, 1959) is an american actor and director. Sep 23, 1959 in newark, new jersey. Jay scott greenspan, better known by his professional name of jason alexander, is an american actor, writer, comedian, television director and producer, .
