Obsessions are commonly described as intrusive, ego-dystonic, and coming out of nowhere. This might reflect an experience of a low sense of agency (SoA; i.e., the experience of being the source of one’s own thoughts). In this study, we investigated the relationship between obsessive-compulsive (OC) symptoms and the SoA over thoughts. Participants were told that subliminal auditory primes (actually sham) can insert thoughts into their minds, and their experiences of inserted thoughts were collected online. The results of three experiments showed reduced SoA over thoughts in individuals with subclinical OC symptoms, regardless of the valence of the thoughts. Several potential confounding factors (e.g., suppression, vigilance, general anxiety) were ruled out. The experience of inserted thoughts was related to experiencing thoughts as “out of context,” which partially explained reduced SoA in participants with high levels of OC symptoms. These experiments highlight the importance of focusing on the low-level, contextual, and phenomenological characteristics of intrusive thoughts in addition to their content and appraisals.