Citizen science projects are an increasingly popular way to engage the public in the process of science. However, few studies have evaluated learning outcomes beyond knowledge gains in formal learning settings with youth. This study evaluated the effects of a classroom-based citizen science project in which middle and high school students collected data about hummingbirds and their habitat use as part of a long-term study on declining hummingbird populations. We explored changes in science identity, nature connectedness, and knowledge of curricular material using quantitative pre- and post-test questionnaires (n = 367). While curricular knowledge scores increased modestly, the project had no meaningful impacts on science identity or nature connectedness. Nevertheless, students reported that the citizen science aspect motivated them and made them feel that they were contributing to science. Results suggest that, while citizen science has potential as an effective mode for educating students about the processes and content of science, one should not assume that it necessarily conveys additional benefits.Supplemental data for this article is available online at https://doi-org.bibliotheek.ehb.be/10.1080/13504622.2021.1927990 .