Citizen science (CS) is a growing field of participatory science, bringing together the public, researchers, organizations, and communities to participate in various scientific projects that unfold in different sociomaterial settings known as territories. While research on perceived learning in CS has recently grown, the discussion regarding the different learning approaches, territories, and the overall process as well as their associations with learning factors remains meager. In our study, we unpack three types of learning (formal, informal, and nonformal) and their respective territories in CS, and within this context, review a model of learning to synthesize the project-related and individual factors associated with the perceived learning of citizen scientists engaged in CS activities. We conducted an international survey for adults participating in CS, which was then analyzed using exploratory factor analysis (N = 596). We identified the following five factors regarding CS activities and perceived learning: sociomaterial learning, social learning, reflective learning, situational learning, and material learning. We found that perceived learning was lower for citizen scientists who participated in biology CS projects but higher among citizen scientists who participated in the long term and engaged in a variety of CS activities. Our findings highlight that the learning experiences of citizen scientists can be varied within a CS project because of the varied entanglements of project-related and individual factors, which can be better understood through a model of learning. Our findings contribute to developing further the theories and practices related to CS and CS in education.