[2] In 1971, Hislop co-founded the Community Homophile Association of Toronto, one of Canada's first organizations for gays and lesbians.
The following year, Hislop ran in the 1981 provincial election as an independent candidate in St. George to protest against the 1981 Toronto bathhouse raids.
Also that year, Hislop was one of several gay activists who launched a class action lawsuit against the federal government.
On November 26, 2004, the lawsuit ended in victory for Hislop and his coplaintiffs, although the federal government subsequently filed a controversial appeal of the decision.
[4] In 2005, Hislop was the first-ever recipient of the International Lesbian and Gay Law Association's Karl Heinrich Ulrichs Award in honour of his contributions to the advancement of LGBT equality in Canada, and was cited by federal New Democratic Party leader Jack Layton as an important influence on Layton's support of LGBT issues.
[5] In an obituary notice, Eye Weekly referred to Hislop as "the unofficial mayor of the Toronto gay community".