Blair was born in Detroit, Michigan. He attended L'Anse Creuse High School-North in Macomb Township, Michigan, where he played tennis. After graduating, he made appearance in commercials for Taco Bell, Pizza Hut and the Honda Civic. In his professional career, Jayson has appeared in many films and television series, including starring in The Hard Times of RJ Berger from 2010-2011, The New Normal from 2012-2013, and a five-episode arc in fellow Freeform series, Young & Hungry. Most recently, he starred in The CW series Life Sentence.