Aim: To evaluate the impact of relevant patient-level characteristics on the efficacy and safety of subcutaneous, once-weekly semaglutide in subjects with type 2 diabetes. Materials and Methods: Exploratory post hoc analyses of pooled SUSTAIN 1-5 (phase 3a) randomized, controlled trials examined the change from baseline in HbA1c and body weight (BW), and the proportions of subjects achieving the composite endpoint (HbA1c < 7.0% [53 mmol/mol]), without weight gain or severe/blood glucose-confirmed symptomatic hypoglycaemia at week 30 with semaglutide (0.5/1.0 mg) across clinically relevant patient subgroups: baseline HbA1c (≤7.5%, >7.5%-8.0%, >8.0%-8.5%, >8.5%-9.0% and > 9.0%), background medications, diabetes duration and pancreatic beta-cell function. Results: Mean HbA1c (% point) reductions increased from lowest to highest HbA1c subgroups (−0.9%, −1.2%,-1.5%, −1.7% and −2.3% [effect of subgroup within treatment: P = 0.247] for semaglutide 0.5 mg, and −1.1%, −1.4%, −1.9%, −2.1% and −2.7% [P = 0.045] for semaglutide 1.0 mg), with mean HbA1c ranges at week 30 of 6.3%-7.3% and 6.1%-6.9%, respectively. The corresponding BW reductions generally decreased with increasing baseline HbA1c (−4.4, −3.9, −3.9, −3.3 and −2.9 kg [P = 0.004], and −6.4, −5.9, −5.2, −4.5 and −4.8 kg [P < 0.001], respectively). HbA1c and BW reductions were consistently greater for semaglutide 1.0 mg versus 0.5 mg across background medication, diabetes duration and pancreatic beta-cell function subgroups. Adverse events with semaglutide were consistent with the glucagon-like peptide-1 receptor agonist class, with gastrointestinal events the most common. Conclusions: Semaglutide was consistently efficacious across the continuum of diabetes care in a broad spectrum of patient subgroups with a range of clinical characteristics.