Hailed by Forbes as one of the 500 wealthiest persons in the United States, James Clark is best recognized as the founder of Silicon Valleytechnology companies which include Netscape Communications Corporation, Healtheon, myCFO, and Silicone Graphics Inc. As of June 2016, James Clark's net worth is estimated to be around $1.79 billion according to Forbes.

After taking his bachelor's and master's degree in Physics at the University of New Orleans, James Clark finished his PhD in computer science  at the University of Utah. After leaving the academe as a student, he was hired at the University of California, Santa Cruz as an assistant professor. He then worked at Stanford University as electrical engineering associate professor.

It was in 1982 when he founded the Silicon Graphics, Inc.. The company grew into a leading provider of 3d imaging and movie visual effects. He left the company in early 1990s and founded Netscape in 1993 with Marc Andreessen. With Internet boom, such endeavor earned him $2 billion. Shortly, his interest to streamline paperworks in the healthcare industry led him to found WebMD.

After three failed marriages, James Clark is currently on his fourth marriage. It was in September 2011 when his fourth wife, Kristy Hinze, gave birth to their first child together. Clark has two children from previous marriages. His daughter Kathy is married to the co-founder of YouTube, Chad Hurley.