Background: Continued participation after sport-related concussion (SRC) worsens outcomes, but it is unknown if duration of continued participation after SRC impacts recovery outcomes, and which athletes who continue to participate are at greatest risk for poor SRC outcomes. The purpose of this National Collegiate Athletic Association/Department of Defense (NCAA/DoD) Concussion Assessment, Research, and Education (CARE) Consortium study was to evaluate the association of estimated duration of continued participation after SRC with symptom severity and recovery time in collegiate athletes. Methods: Clinicians estimated if/how long athletes continued participation after SRC. Collegiate athletes who continued participation after suspected SRC (n = 195/373, 52.3%) completed the Graded Symptom Checklist to evaluate the severity of total symptoms and migraine/fatigue, cognitive/ocular, and affective symptom clusters. Linear regression analyzed the associations between estimated duration of continued participation, symptom severity, and recovery time. Binary logistic regression examined the association of estimated duration of continued participation with the odds of recovery ≥ 14 and ≥ 21 days. Statistical significance was p < 0.05. Results: Athletes who continued to participate did so for 27.9 ± 25.3 min (mean ± standard deviation; range 1–90 min). Longer estimated continued participation (1–90 min) was associated with greater symptom severity (β = 0.122, p = 0.02), affective (β = 0.171, p = 0.001) and migraine/fatigue symptoms (β = 0.104, p = 0.049), longer symptom duration (β = 0.193, p < 0.001), and longer time missed (β = 0.156, p = 0.003). Longer estimated continued participation positively interacted with female sex (cognitive/ocular: female R2 = 0.03, male R2 = 0.01, p = 0.02; affective: female R2 = 0.06, male R2 = 0.02, p = 0.006), migraine history (affective symptoms: no migraine R2 = 0.02; migraine R2 = 0.18; p = 0.04), and concussion history (affective: 2 + prior concussions [R2 = 0.14] compared with those with 1 [R2 = 0.07] or 0 [R2 < 0.01] prior concussions [p = 0.003]). Conclusions: Longer estimated duration of continued participation after SRC was associated with higher symptom severity, particularly affective and migraine/fatigue; longer symptom duration; and more time missed from sport. SRC outcomes in those who continue to play may be especially severe for female athletes, athletes with migraine history, and athletes with prior concussion(s). The findings can help clinicians and administrators to educate athletes on the importance of immediate removal following a suspected SRC.