Helquist was born in Ganado, Arizona. Shortly after graduation from Brigham Young University in Provo, Utah in 1993 with a Bachelor of Fine Arts, he moved to New York City, where he currently lives with his wife, Mary Jane Callister. He has illustrated for many magaziines, newspaper, and publishing clients including: The New York Times, TIME for Kids, Harper Collins, and Farrar Straus and Giroux. He is best known as the illustrator of the seven titles in the Series of Unfortunate Events, published by Harper Collins.