Heather Mason is a Canadian prison reform advocate, sex segregationist, and anti-transgender activist. Mason is a founding member of anti-trans group Canadian Women’s Sex-Based Rights (caWsbar).
Mason is formerly federally incarcerated. Since release, Mason has been a prominent opponent of accommodations for transgender prisoners, especially trans women being housed in women’s prisons.
Background
Mason started using drugs at a young age, which eventually led Mason to be incarcerated five times provincially and once federally at the Grand Valley Institution for Women in Kitchener, Ontario.
Mason earned a personal support worker certificate from Lambton College in 2010 and a certificate in teaching preparation for the International English Language Testing System (IELTS) from the Canadian College of Educators in 2019.
From 2011 to 2014, Mason woked as a contract personal support worker via Canadian Red Cross. Mason has taught English as a second language at Eton Academy and Caesar International Academy. From 2021 to 2023, Mason was a peer researcher at Unity Health Toronto, researching the needs of people released from custody during the COVID pandemic.
Mason is a member of the Strength in SISterhood (SIS) Society.
Anti-trans activism
In 2023, Mason wrote:
“In 2019 I began documenting the impact of males in women’s prisons, speaking to women newly released and to women inside to ensure that their voices are not silenced. Working with other advocates, we created a survey and collected data from an even wider array of women on what they experienced while inside. We amalgamated statistics and highlighted nuanced examples from the data we collected – this data has informed the articles I have written, and testimony I have provided to Parliament. With the support of the Canadian Women’s Sex-Based Rights (caWsbar) and We The Females (WTF), I organized a series of Keep Prisons Single Sex protests in Kitchener, outside of Grand Valley prison. Since our first protest in 2021, we have put on 19 additional protests, including two days of national protests.”
On April 7, 2025, Justice Centre for Constitutional Freedoms lawyers filed a lawsuit on behalf of Canadian Women’s Sex-Based Rights (caWsbar) with the Federal Court of Canada in Toronto. Their lawsuit asked the Federal Court to review Correctional Service Canada’s Commissioner’s Directive 100: Gender Diverse Offenders and declare that the directive is of no force or effect
References
Staff report (April 21, 2022). Pursuit 365 Day 111: Heather Mason. Fresh Magazine https://freshmag.ca/pursuit-365-day-111-heather-mason/
Anti-trans coverage
Greenberg, Courtney (June 5, 2026). Transfers of trans prisoners in Canada have fallen. An upcoming case will test gender policies. National Post https://nationalpost.com/news/trans-women-prisoners-correctional-institution
Justice Centre for Constitutional Freedoms (May 14, 2026). The forcible confinement of female inmates with trans-identifying males is challenged in court. https://www.jccf.ca/court_cases/the-forcible-confinement-of-female-inmates-with-trans-identifying-males-is-challenged-in-court/
Selected writing by Mason
Phoenix, Jo; Mason, Heather (February 2023). Rights and Wrongs: How gender self-identification policy places women at risk in prison. Macdonald-Laurier Institute https://macdonaldlaurier.ca/wp-content/uploads/2023/02/20230117_Rights_and_wrongs_Phoenix_PAPER_FWeb.pdf
Mason, Heather (October 6, 2021). Segregation and Bill C-83: An Act to amend the Corrections and Conditional Release Act and another Act. Strength in Sisterhood Society https://www.strengthinsisterhood.net/the-issues
Mason, Heather (June 22, 2021). Brief submitted by Heather Mason on the Current situation in federal prisons in
relation to reports of sexual coercion and violence in federal prisons. Presented to the Canadian House of Commons, Standing Committee on Public Safety and National Security https://www.ourcommons.ca/Content/Committee/432/SECU/Brief/BR11468302/br-external/MasonHeather-e.pdf
Mason, Heather (May 24, 2021). [Written testimony against Maine LD 1044 (HP0772), which outlined protections and guidelines for transgender incarcerated individuals within the state’s correctional system]. https://legislature.maine.gov/testimony/resources/CJPS20210518Mason132664243382187374.pdf
Mason, Heather (December 5, 2019). The alarm has been sounded, who’s going to respond? Women Are Human https://www.womenarehuman.com/the-alarm-has-been-sounded-whos-going-to-respond/
Media
The New Westminster Times with Amy Hamm and Heather Mason (June 1, 2026). Prison Nightmare? Shocking Stories of Male Predators in Women’s Jails. https://www.youtube.com/watch?v=H5p978nYKxw
The Red Tent Collective / North American Angst with Peeja Blackbird, Carol Blackbird Edson, Amie Ichikawa, and Heather Mason (uploaded January 19, 2026). N.A.A. from the Archives: Heather Mason & Amie Ichikawa on Keeping Prisons Single Sex #KPSS. https://www.youtube.com/watch?v=Nzc1j_j_xT0
Western Standard with Jeremy Borg and Heather Mason (September 21, 2025). Advocacy group says ‘trans women’ in women’s prison is endangering female inmates. https://www.youtube.com/watch?v=Ym7aK20mR-I
The News Forum / Counterpoint with Tanya Granic Allen, Linda Blade, and Heather Mason (April 15, 2025). Is there a safe place to wrestle with women’s rights and transgender rights? https://www.youtube.com/watch?v=j4pD7YJg8Lo
Rebel News with Keean Bexte and Heather Mason (Mar 19, 2024). ‘It is dangerous’: Activist addresses concerns about allowing male inmates in female prisons. https://www.youtube.com/watch?v=a5DEha_YwFs
Rebel News with Tamara Ugolini and Heather Mason (September 7, 2022). Transgenderism: A threat to women’s privacy, security, and safety. https://www.youtube.com/watch?v=h_RTW4cglO8
The News Forum / Counterpoint with Tanya Granic Allen and Heather Mason (November 27, 2023). Disturbing Stories Coming Out Of Women’s Prisons Since Biological Males Started Transferring. https://www.youtube.com/watch?v=po3mCC8bsFU
Juno News / Ratio’d with Harrison Faulkner and Heather Mason (November 23, 2023). SCANDAL: Violent men wreaking havoc inside women’s prisons. https://www.youtube.com/watch?v=4LiU_D1Dz2w
Allie Beth Stuckey with Heather Mason (September 11, 2023). Former Prisoner on the Dangers of Men in Women’s Prisons | Guest: Heather Mason | Ep 870. https://www.youtube.com/watch?v=CbKnqW7bJjY
Rebel News with Keean Bexte and Heather Mason (June 13, 2023). Protest erupts against policy allowing violent biological male sex offenders in women’s shelters. https://www.youtube.com/watch?v=Vr3lKlPLw2U
Calmversations with Benjamin Boyce and Heather Mason (January 25, 2022). Pandemic Impacts: Canadian Prisons | with Heather Mason. https://www.youtube.com/watch?v=pPnpLULKk6o
The Countess with Rhona Hotchkiss, GearĂłid O Loingsigh, and Heather Mason (April 13, 2021). Mixed-Sex Prisons #1 – Rhona Hotchkiss, GearĂłid O Loingsigh and Heather Mason. https://www.youtube.com/watch?v=PFxrojXJol4
Women’s Declaration International with Jo Brew, Kate Coleman, Florence Humbert, Jessica Williams, and Heather Mason (April 5, 2021). Women in Prison: Heather Mason founding member of CaWsbar Canada – FQT 03 April 2021. https://www.youtube.com/watch?v=SyN47rJeL5w
Women’s Liberation Radio News with Heather Mason, Joey Twins, and Alia Pierini (February 21, 2020). Women’s Prisons: What are they *really* like | Heather Mason. https://www.youtube.com/watch?v=ytSARKP0D14
Meghan Murphy with Healther Mason (December 10, 2019). Heather Mason on the transferring of males to women’s prisons in Canada. https://www.youtube.com/watch?v=GrxdLNg8-gs
Resources
Canadian Women’s Sex-Based Rights (cawsbar.ca)
- Steering Committee: Heather Mason
- cawsbar.ca/steering-committee
X/Twitter (x.com)
LinkedIn (linkedin.com)
Facebook (facebook.com)
- heather.mason.79656921 [restricted]
GoGetFunding (gogetfunding.com)
- Heather Mason: Canadian Women’s Prisons
- gogetfunding.com/canadian-womens-prisons
Strength in Sisterhood Society (strengthinsisterhood.net)