Gerry Martiniuk is a politician in Ontario, Canada. He is currently a member of the Legislative Assembly of Ontario, representing the riding of Cambridge for the Progressive Conservative Party.

Martiniuk was born in Toronto, and was educated at the Osgoode Hall Law School at York University, receiving an LL.B. in 1962. He was director of the St. John Ambulance organization before entering provincial politics, as well as serving as president of the Cambridge Chamber of Commerce.

Martiniuk began his career at the provincial level, serving as a school trustee on the Waterloo County Board of Education, an alderman in Preston , chair of the Waterloo Regional Police Commission, and a municipal councillor in Cambridge.

In the 1995 provincial election, he was elected in Cambridge over incumbent New Democrat Mike Farnan (Cambridge was one of several working-class ridings that shifted from the NDP to the Tories to his cycle). He was easily re-elected in the 1999 election, defeating Liberal Jerry Boyle by over 14,000 votes. Although he served as a Parliamentary Assistant to various ministers, he was never appointed to Cabinet by Mike Harris or Ernie Eves.

The Tories were defeated in the provincial election of 2003, although Martiniuk was again re-elected, this time defeating Boyle by just over 3000 votes. In 2004, he supported John Tory's successful bid replace Eves as provincial PC leader.