The son of Ukrainian immigrants, Sitarchuk was born in Philadelphia. After attending Temple University's Tyler School of Art, he served in the United States Army in World War II. On returning to Philadelphia, he dedicated himself to making sculpture and teaching. A beloved instructor for many decades, Sitarchuk taught at the Museum School of Industrial Art (now University of the Arts), the Philadelphia Museum of Art, the Cheltenham Art Center, and Woodmere. His impact on the field of sculpture lives on through the many artists who think of him as a primary inspiration and mentor, particularly Dina Wind, whose sculpture is across the field.