Objective The successful recruitment and study of cancer survivors within psycho‐oncology research can be challenging, time‐consuming, and expensive, particularly for key subgroups such as young adult cancer survivors. Online crowdsourcing platforms offer a potential solution that has not yet been investigated with regard to cancer populations. The current study assessed the presence of cancer survivors on Amazon's Mechanical Turk (MTurk) and the feasibility of using MTurk as an efficient, cost‐effective, and reliable psycho‐oncology recruitment and research platform. Methods During a <4‐month period, cancer survivors living in the United States were recruited on MTurk to complete two assessments, spaced 1 week apart, relating to psychosocial and cancer‐related functioning. The reliability and validity of responses were investigated. Results Within a <4‐month period, 464 self‐identified cancer survivors on MTurk consented to and completed an online assessment. The vast majority (79.09%) provided reliable and valid study data according to multiple indices. The sample was highly diverse in terms of U.S. geography, socioeconomic status, and cancer type, and reflected a particularly strong presence of distressed and young adult cancer survivors (median age = 36 years). A majority of participants (58.19%) responded to a second survey sent one week later. Conclusions Online crowdsourcing represents a feasible, efficient, and cost‐effective recruitment and research platform for cancer survivors, particularly for young adult cancer survivors and those with significant distress. We discuss remaining challenges and future recommendations. Copyright © 2016 John Wiley & Sons, Ltd.