John-Mark Gleadow was born in Milford, Delaware on April 4 th , 1976. Except for the period he attended the University of Delaware in Newark, he's lived and worked in Lincoln, Delaware.

With his formal art training ending in the fourth grade, the focus of John-Mark's schooling culminated with his being accepted into the University of Delaware as a Mechanical Engineering major. He had also received a congressional nomination to attend West Point. Loathing the technical restraints of engineering, John-Mark changed majors to what is purely design – art. Never having painted before and mainly having experience only with graphite, John-Mark was initially discouraged by his lack of control over oil paint and even stopped attending his Intro to painting class. But mainly by spending time by himself in the studio, he began to gain control over the new medium so that his final project for the class was accepted into year's juried undergraduate show at the university – where it won the painting award, and eventually sold for $1,000 at a Washington, D.C. gallery. John-Mark went on to graduate with a Bachelor of Fine Arts degree with a concentration in painting in the winter of 1999.

With the support of his family John-Mark has worked as professional artist since graduating from college. He's shown his work with galleries in New Mexico, New York, Baltimore and Washington, D.C., along with galleries in his home state in Wilmington, Dover and Rehoboth Beach. Along with the awards his work has garnered over the years, John-Mark was also the honored recipient of an Emerging Artist's Grant from the Delaware Division of The Arts in 2002 and a $15,000 Fellowship from the Savannah College of Art and Design awarded him in 2005.