We evaluated baseline characteristics of participants with early-onset type 2 diabetes (T2D) from the SURPASS program and tirzepatide's effects on glycemic control, body weight (BW), and cardiometabolic markers. This post hoc analysis compared baseline characteristics and changes in mean HbA1c, BW, waist circumference (WC), lipids, and blood pressure (BP) in 3,792 participants with early-onset versus later-onset T2D at week 40 (A Study of Tirzepatide [LY3298176] in Participants With Type 2 Diabetes Not Controlled With Diet and Exercise Alone [SURPASS-1] and A Study of Tirzepatide [LY3298176] Versus Semaglutide Once Weekly as Add-on Therapy to Metformin in Participants With Type 2 Diabetes [SURPASS-2]) or week 52 (A Study of Tirzepatide [LY3298176] Versus Insulin Degludec in Participants With Type 2 Diabetes [SURPASS-3]). Analyses were performed by study on data from participants while on assigned treatment without rescue medication in case of persistent hyperglycemia. At baseline in SURPASS-2, participants with early-onset versus later-onset T2D were younger with longer diabetes duration (9 vs. 7 years, P < 0.001) higher glycemic levels (8.5% vs. 8.2%, P < 0.001), higher BW (97 vs. 93 kg, P < 0.001) and BMI (35 vs. 34 kg/m2, P < 0.001), and a similarly abnormal lipid profile (e.g., triglycerides 167 vs. 156 mg/dL). At week 40, similar improvements in HbA1c (-2.6% vs. -2.4%), BW (-14 vs. -13 kg), WC (-10 vs. -10 cm), triglycerides (-26% vs. -24%), HDL (7% vs. 7%), and systolic BP (-6 vs. -7 mmHg) were observed in both subgroups with tirzepatide. Despite younger age, participants with early-onset T2D from the SURPASS program had higher glycemic levels and worse overall metabolic health at baseline versus those with later-onset T2D. In this post hoc analysis, similar improvements in HbA1c, BW, and cardiometabolic markers were observed with tirzepatide, irrespective of age at T2D diagnosis. Future studies are needed to determine long-term outcomes of tirzepatide in early-onset T2D.