The House vote was 117-1. Senators passed the bill unanimously Friday.
The bill would require motorists to stay at least 10 feet from a stopped school bus. Violators could be fined up to $750 for a first offense. On a second offense, violators face a fine and up to a year in prison.
The bill is named for Nathan Key, a Jones County boy who was killed after getting off a school bus in 2009.
Nathan's father, Andy Key, watched Saturday as the House passed the bill. He says he hopes it helps protect children's safety.
The bill is Senate Bill 2472.