He worked for twenty years as a professor at Case Western Reserve University and later served as the Chairman of Oxford Bioscience Corporation.

[1] After finishing his doctoral program, Walton moved to the United States where he initially taught and did postdoctoral research at the University of Indiana.

[12] The following year, in coordination with Helga Furedi-Milhofer, Walton became the director of a joint research project with the Ruđer Bošković Institute in Zagreb, Yugoslavia (present-day Croatia).

[10] Among the results of that committee's work was the Bayh–Dole Act of 1980, which allowed universities to commercially license technology arising from federal government-funded research.

In 2012, Queen Elizabeth II awarded Walton the Order of the British Empire (OBE) for "services to the UK biotechnology industry.

[20] Walton's first foray into the business world was a part-time job running Biopolymer Corporation, a company he founded while still at Case Western in 1978.

[21] The company manufactured and sold biopolymers, and employed many of the post-doc and grad students that Walton knew from his teaching career.

In an interview with The New York Times, Walton said "My new company addresses the problem—raising money from the public sector and funding research at universities.

"[21] In 1983, the company went public and in 1986 it completed a secondary offering in which the original investors were bought out for $3.6 million, giving them a sixty-fold return on investment in five years.

[24] According to the firm, Walton was probably the first former tenured professor of molecular biology in the venture capital industry, which then was mainly run by businesspeople with little bio-technical understanding.

[25][26] Around the same time, Walton helped Venter set up The Institute for Genome Research, a non-profit the discoveries of which were marketed by HGS.

[24] Walton also continued to fly small planes, drawing on the training he gained in the Royal Air Force Volunteer Reserve.

[29] He was one of the first 100 people to pay for a trip into space through Virgin Galactic in 2004; after years of delays in getting the project off the ground, Walton was forced to ask for a refund in 2011, citing his advanced age.