He was a Liberal member of the Legislative Assembly of Ontario from 2003 to 2011 and again from 2014 to 2018 who represented the ridings of Northumberland and Northumberland—Quinte West.

As mayor, he presided over the establishment of the Brighton Health Services Centre in the community.

[1] The Liberals won the election, and Rinaldi was named Parliamentary Assistant (PA) to David Caplan, the Minister of Infrastructure, on October 23, 2003.

In the provincial election of 2011 he was defeated by Progressive Conservative candidate Rob Milligan.

[4][5] In July 2014, he was reappointed as Parliamentary Assistant to the Minister of Municipal Affairs and Housing.