Born in 1937 and raised in Brooklyn, Michigan and Chicago provided experiences of both urban and rural settings which inspired his drawing and painting at a young age. Son of a Lutheran Pastor they frequently moved to different parishes however his father always encouraged his artistic exploration even in the backseat of the family car on trips out east.

As a senior at Austin High School he was the sole recipient in Chicago to receive a scholarship to The School of the Art Institute of Chicago. This prestigious award confirmed his artistic and academic direction towards fine art. ultimately, he decided to attend Luther College in Iowa to develop a liberal arts background and earn his BFA.

From this point, The University of Iowa provided him with painting and printmaking coursework. Mauricio Lasansky, one of the finest engravers during the 60s, provided the critical instruction which led to John's passionate interest in the process and unique media of engraving. The process of printmaking and his interest in color through painting became a major focus in his artistic expression. He explained that printmaking informed his creative direction in painting. Finally, in 1963 he earned his Master of Fine Arts in Printmaking and Painting as well as a minor in Art History.

As an educator working with students provided lively interactions which inspired him towards a teaching career. From 1963-64 he taught art classes at West Elementary School and also became an adjunct faculty member at Silvermine College of Art in New Canaan, Connecticut. On his return to the Chicago area he taught art at Mount Prospect High School.

In 1967, Harper College was being built in Palatine so he applied and became the very first professor hired to the College. He was instrumental in developing the Fine Arts Department, The National Juried Exhibition and the Foundation Art Collection. Knudsen also had a profound impact on his students during his successful teaching career and maintained a prolific artistic practice. His tenure lasted 31 years until 1998. During his tenure probably the single most important influence was when he was awarded a sabbatical to study with Stanley William Hayter at Atelier 17 in Paris.

After retiring he devoted his time exploring his creativity through painting, etching and woodcut media at his gallery, The John A. Knudsen Workshop/Gallery in Union Pier, Michigan from 1993 until his death in 2014.

During the month of September, 2015, John was honored with a retrospective showing of his work at Harper College in Palatine.