This research examined the differential motivational effects of a pre-college science enrichment program delivered in both online and in-person learning formats. Using self-determination theory as a guiding framework, we hypothesized that (1) students would exhibit growth in their perceived satisfaction of needs for autonomy, competence, and relatedness, (2) online learning would be associated with greater growth in autonomy, and (3) in-person learning would be associated with greater growth in both competence and relatedness. Using a sample of 598 adolescent participants, results of latent growth curve modeling indicated that satisfaction of the three needs grew unconditionally over the course of the program. However, format type was unrelated to growth in need satisfaction. Rather, this effect was found to be conditional upon the type of science project undertaken by students: astrophysics students exhibited significantly greater autonomy growth when receiving online instruction than did biochemistry students. Our findings suggest that online science learning can be just as effective in motivating students as in-person learning provided that the learning tasks are conducive to remote instruction.