"New York needs to act now to make marijuana legally available for medical use," Williams said.
The New Yorker said he bought the drug legally through a state-sanctioned commune in California to alleviate his pain.
Lawmakers and health officials joined Williams in backing legislation that would let doctors prescribe medical marijuana if no other medication would be as effective, Newsday reported Wednesday.
Patients could possess no more than 2.25 ounces.
Observers said support, including that of Senate Majority Leader Joseph Bruno, could bring the bill to Gov. George Pataki's desk.
Opponents said the measure could lead to more extensive legalization of the drug, which 12 states permit for medicinal use.
The U.S. Supreme Court was considering whether state laws violate a federal ban.