Background: Initiating and maintaining exercise is challenging for women during and post-cancer treatment. Adopting a peer partner model to provide social support to be active may contribute to lasting behaviour change of both partners. Despite this, nding a 'like peer' can be challenging.Purpose: To explore women's reasons for seeking an online exercise partner following a diagnosis with cancer (through www.activematch.ca). We also examined women's potential socio-demographic and cancer-related differences by reported reasons for wanting an exercise partner.Methods: Individuals creating an Active Match pro le completed demographic and physical activity questions (N=199, Mage(SD)=51.9(10.8) years), including an open-ended question regarding their 'reason for wanting an exercise partner'. An inductive content analysis was completed focusing on the participants' peer exercise partner preferences. Additional chisquare tests were run to assess whether participants differed based on sociodemographic and cancer-related characteristics and their motivations to be active by category of 'reason for wanting an exercise partner' endorsed in the open-ended question.Results: The participants' reasons for wanting an exercise partner were coded into seven categories, with most participants highlighting the reasons of: motivation (52.3%), social support (48.7%), and accountability and adherence (26.6%). Women <50 years of age were more likely to report accountability and adherence related preferences for a partner. Those reporting endorsing weight loss as their primary reason for becoming active were more likely to be categorized as wanting a peer partner for motivation.Conclusions: While nding a peer partner can be challenging, matching women living with and beyond a cancer diagnosis based on their reason for wanting an exercise partner, as well as their reasons for wanting to be active, may be important to build successful peer exercise partnerships.Health, 18(1), 15579883231215153.