Background: Favorable outcomes after anterior cruciate ligament (ACL) reconstruction (ACLR) are often gauged by successful return to play (RTP), a low incidence of subsequent ACL injury, and positive patient-reported outcomes. Level 1 sports place the highest demands on the knee by requiring frequent pivoting, changes in direction, and jumping. Purpose: To analyze the outcomes of primary ACLR in level 1 athletes and identify pre- and intraoperative factors associated with RTP, ipsilateral ACL reinjury, contralateral ACL injury, and International Knee Documentation Committee (IKDC) score at 5 years postoperatively. Study Design: Cohort study; Level of evidence, 2. Methods: A consecutive cohort of 1432 patients who underwent primary ACLR by 2 orthopaedic surgeons were prospectively evaluated. The RTP rate, incidence of ipsilateral/contralateral ACL injury, and IKDC score were analyzed at 5 years. Comparative analysis of clinical variables was performed between those who achieved favorable outcomes and those who did not. Outcomes at 5 and 2 years were also compared. Results: The mean age was 24.3 ± 7.3 years (males: 75%, females: 25%). Gaelic football was the predominant sport (40%), followed by soccer (19%). The RTP rate was 87.4%, with 59.8% of athletes still playing at an equivalent or higher level at 5 years. The incidence of ipsilateral reinjury for athletes who resumed level 1 sport was 4.3% for bone–patellar tendon–bone (BPTB) autografts with screw fixation and 19.7% for hamstring tendon (HT) autografts with EndoButton and screw fixation. The incidence of contralateral ACL injury was 13.7%. The mean IKDC score at 5 years (86.6 ± 10.9) was comparable to that at 2 years (86.8 ± 10.1). Patients were more likely to RTP with each year of decreasing age (OR, 1.06; P < .001), with a higher preoperative Marx score (OR, 1.08; P < .001) or a higher 5-year IKDC score (OR, 1.06; P < .001). The risk of ipsilateral ACL reinjury increased each year of decreasing age (OR, 1.11; P < .001) or when an HT autograft was used (OR, 5.56; P < .001). Younger age was also associated with contralateral ACL injury (OR, 1.1; P < .001). Female sex, older age, concomitant meniscal/chondral injuries, and lower preoperative Anterior Cruciate Ligament Return to Sport after Injury scores were associated with lower IKDC scores at 5 years. Conclusion: Most patients could return to level 1 sports, although their performance level was impacted. Those who returned to sport maintained their performance level over the 5 years. The ipsilateral reinjury rate for BPTB autografts with screws was significantly lower than that for HT autografts with EndoButton and screw fixation. Most ACL reinjuries occurred between 2 and 5 years of follow-up. Younger patients had an increased risk of a subsequent ACL injury to either knee, regardless of graft type. IKDC scores were lower in female patients, older patients, and those with concomitant meniscal/cartilage injuries. Registration: NCT02771548 (ClinicalTrials.gov identifier).