Background: Outdoor education may positively impact the educational, physical, and emotional development of youth, but studies are sparse among urban children. Purpose: To investigate 1) physical activity (PA) levels in outdoor versus indoor education environments, 2) science learning gains during outdoor education, and 3) programmatic acceptability among children from an urban, low-income school district attending an outdoor education program. Methods: N = 69 were randomly chosen from 571 4th graders participating in an outdoor education program. PA levels were measured using accelerometers; science knowledge was measured using a pre-post assessment; acceptability was assessed using a questionnaire. Results: Students took part in over an hour more of moderate to vigorous physical activity (MVPA) (p < 0.05) and increased the proportion of time spent in MVPA by 25% (p < 0.05) on outdoor education days compared to indoor school days. Science knowledge improved significantly pre- to post participation (p < 0.01). Students reported high levels of enjoyment and science learning engagement. Teachers reported the experience increased students' PA levels and improved students' science knowledge. Discussion: School districts may be able to leverage outdoor programs with community partners to promote PA and simultaneously improve science learning. Translation to Health Education Practice: Community partnerships can help urban youth from under-resourced schools meet PA recommendations and improve academic performance through outdoor education programming.