Morris attended Harvard University, and later went on to graduate school at Cornell University. During his first year there, he designed a computer worm that disrupted many computers on what was then a fledgling internet.
This led to him being indicted a year later.
After serving his conviction term, he returned to Harvard to complete his Doctor of Philosophy under the supervision of H.T. Kung. He finished in 1999.
In 1989, Morris was indicted for violating United States Code Title 18, the Computer Fraud and Abuse Act.
He was the first person to be indicted under this act.
In December 1990, he was sentenced to three years of probation, 400 hours of community service, and a fine of $10,050 plus the costs of his supervision.
He appealed, but the motion was rejected the following March. Morris' stated motive during the trial was "to demonstrate the inadequacies of current security measures on computer networks by exploiting the security defects had discovered."
He completed his sentence as of 1994.
Morris' principal research interest is computer network architectures which includes work on distributed hash tables such as Chord and wireless mesh networks such as Roofnet.
He is a longtime friend and collaborator of Paul Graham. Along with cofounding two companies, Graham dedicated his book ANSI Common Lisp to Morris, and named the programming language that generates the online stores' web pages RTML in his honor. Graham lists Morris as one of his personal heroes, saying "he's never wrong