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, finding a "like peer" can be challenging. 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 sociodemographic and cancer-related differences by reported reasons for wanting an exercise partner. Individuals creating an ActiveMatch profile 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 chi-square 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. 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 < 50years 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. While finding 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.