In October 2016, Oosterhoff was nominated as the Progressive Conservative candidate in
Niagara West—Glanbrook to replace
Tim Hudak, who resigned his seat that September. Former MP and current president of the Progressive Conservative Party of Ontario
Rick Dykstra was the favoured candidate by both the party establishment and PC leader
Patrick Brown, but Oosterhoff had more local support, including that of his church. Social conservatives such as
Charles McVety accused Brown of muzzling Oosterhoff during the campaign because of the candidate's opposition to the new
sexual education curriculum. On November 17, 2016, Oosterhoff defeated
New Democratic challenger Mike Thomas by 9,528 votes. Brown said the delay was so that Oosterhoff could organize a celebration party for his family and supporters. Oosterhoff is a
social conservative, However, in 2016 he stated that he is “absolutely not” a homophobe. Oosterhoff picked up 24,361 (52.74%) of the vote in the
2018 Ontario general election, defeating NDP candidate Curtis Fric. On June 29, 2018, Oosterhoff was appointed to the role of
Parliamentary Assistant to
Lisa Thompson, the
Minister of Education. Oosterhoff was widely criticized on April 20, 2018, for his televised rendition of African-American spiritual 'Nobody Knows the Trouble I've Seen' given his socially conservative views and trouble-free middle class upbringing. On October 31, 2018,
Halloween, Oosterhoff celebrated the passing of the
Cap and Trade Cancellation Act with a rendition of "
Monster Mash" at
Queen's Park. In May 2019, Oosterhoff participated in an anti-abortion rally at Queen's Park hosted by March for Life, where he made a stage appearance. During his speech at the rally, he said that "We have survived 50 years of abortion in Canada and we pledge to fight to make abortion unthinkable in our lifetime." In October 2020, amid the
COVID-19 pandemic in Ontario, Oosterhoff took group photos with about forty people in a
banquet hall, none of whom were wearing masks or
social distancing, which was contrary to provincial public health measures. Oosterhoff deleted the photos and apologized, saying that he should have worn a mask and that except for the photograph, the group had otherwise distanced. On June 6, 2024, Oosterhoff took office as the Associate Minister of Energy-Intensive Industries. == Personal life ==