Justin Gregory Smith (born January 8, 1978), known professionally as Just Blaze, is an American record producer. Born in Paterson, New Jersey, Smith attended Rutgers University for three years before dropping out to pursue a career in music production. He gained recognition as an in-house producer for Roc-A-Fella Records in the early 2000s, developing the "chipmunk soul" sampling style that was prominent in hip hop during that time.

Smith produced Eminem's 2010 single "No Love" and appeared in its accompanying music video. He has composed soundtracks for video games, and was a character in NBA Street Vol. 2. His stage name was inspired by the character Blaze Fielding from the Streets of Rage video game series. Smith founded the record label Fort Knocks Entertainment in 2004, through which he has signed artists including Saigon and Ms. Jade. He was awarded a key to the city by Paterson in July 2018, in recognition of his "outstanding cultural contribution" to his hometown.

The Grammy Awards are awarded annually by the National Academy of Recording Arts and Sciences. Just Blaze has been nominated 8 times.