Today, the public is exposed to vast amounts of information from innumerable formal and informal scientific and social sources with almost as wide a range of reliability. To gauge reliability, individuals, both young and old, must harness three key types of reasoning: statistical (reasoning with data), scientific (relating the data to scientific theories), and understanding the Nature of Science (how science operates). Cultivating and integrating these forms of reasoning is a priority in contemporary science education but remains under-addressed. This instrumental case study examined how citizen science can foster these critical reasoning skills among 15–16-year-old biology students. Content analysis of the four-part learning sequence revealed that the citizen science pedagogical framework provides opportunities for students’ engagement and cultivation of the three types of reasoning.