Theo Keller developed a taste for fine art at a very early age. He was raised by his parents in a pottery, sculpture and painting studio in Maine. Growing up around artisans and craftsmen, he was able to learn many techniques in various crafts. By the age of 18, Keller already had 8 years of photography experience under his belt, but was attracted to molten glass more than anything.
Keller began his formal apprenticeship in New Mexico under noted sculptor and beadmaker, Lewis Wilson. In subsequent years he also studied under Bandhu Scott Dunham, Tom Hanks, Larry Thornhill, Roger Parramore and ultimately spent two months under the Italian glass master, Emilio Santini. Keller also studied at Penland School of Crafts in North Carolina under Loren Stump.
Keller built his own studio and shortly thereafter in 1999 doubled the size of it to accommodate a growing demand for his work and to create room to work on new designs.