Young adults (YA) are underrepresented in behavioral weight loss programs and achieve poorer outcomes than older adults (OA). There has been a call to develop programs specifically targeting this age group. This study examined the performance of YA enrolled in a low-intensity, team-based weight loss campaign and compared their outcomes to OA to determine the utility of such an approach for weight loss in this population. Shape Up Rhode Island (SURI) 2009 was a 12-week online team-based weight loss and exercise competition (N = 6,795, 81% female, 94% white, age = 44.7 ± 11.2, BMI = 29.4 ± 5.9). YA was defined as 18–35 years and OA as >35 years; YA and OA were compared on enrollment, retention, weight loss, and change in steps. A total of 1,562 YA enrolled and 715 completed the program. Fewer YA completed compared with OA (46 vs. 62%, P < 0.001). However, among completers, YA achieved greater percent weight loss (-4.5 ± 4.0 vs. −3.8 ± 3.2%) and greater daily step change (+1,578.2 ± 3,877.2 vs. +1,342.2 ± 3,645.7) than OA (P's < 0.001). Further, more YA completers achieved a ≥5% weight loss (40 vs. 29%, P < 0.001). Findings were consistent in the overweight/obese (OW/OB) subsample, and using ≤25 years of age as the cut off for YA. Weight losses among YA in this low-intensity weight loss campaign were quite promising, with over 700 YA completing the program and on average achieving a 4.5% weight loss. Indeed, the potential public health impact of such an approach is substantial; future efforts to develop programs for this age group may benefit from using a low-intensity, team-based approach.