Abstract Introduction Inflammation is a pathophysiological process associated with increased cardiovascular (CV) risk, with high-sensitivity C-reactive protein (hsCRP) used as a biomarker to predict CV risk. However, the prevalence of systemic inflammation (defined as hsCRP ≥ 2 mg/L) in contemporary cohorts with high CV risk, including CV disease (CVD), chronic kidney disease (CKD), obesity and/or type 2 diabetes (T2D), is not well characterized. Purpose To evaluate the proportion of individuals with systemic inflammation and the characteristics of individuals with and without systemic inflammation among groups at high risk of CV events, using baseline data from three ongoing randomized, placebo-controlled, phase 3 trials investigating the efficacy of semaglutide versus placebo in high CV risk populations (SELECT, SOUL and FLOW). Methods SELECT (NCT03574597) recruited adults ≥ 45 years old with a body mass index (BMI) ≥ 27 kg/m² and established CVD (previous myocardial infarction, ischaemic or haemorrhagic stroke, or symptomatic peripheral artery disease [PAD]), without diabetes. SOUL (NCT03914326) recruited adults ≥ 50 years old with T2D and at least one of coronary heart disease, cerebrovascular disease, symptomatic PAD or CKD (estimated glomerular filtration rate [eGFR] < 60 mL/min/1.73 m²). FLOW (NCT03819153) recruited adults ≥ 18 years old with T2D and CKD (eGFR ≥ 25–≤ 75 mL/min/1.73 m² and urinary albumin-to-creatinine ratio > 100–< 5000 mg/g) treated with renin-angiotensin-aldosterone system-blocking agents. Baseline hsCRP levels were measured in the three trials. Descriptive statistics were used to analyse the baseline characteristics of participants; p values were calculated with chi-squared tests using Yates’s correction for continuity. Results Baseline characteristics were available for 17 487 individuals from SELECT, 9577 from SOUL and 3519 from FLOW (Table), with systemic inflammation present in 47.2%, 49.5% and 56.8% of the trial populations, respectively. Across trials, PAD and heart failure were significantly more prevalent in individuals with hsCRP ≥ 2 mg/L than in those with hsCRP < 2 mg/L; in addition, CKD stage 3–5 and stroke were more prevalent in groups with hsCRP ≥ 2 mg/L in SELECT and SOUL. The following factors were characteristic of the groups with systemic inflammation in the three trials: female sex, younger age, higher BMI, lower levels of high-density lipoprotein cholesterol, and higher levels of glycated haemoglobin (HbA1c), total cholesterol, low-density lipoprotein cholesterol and triglycerides. Conclusion In these large phase 3 trials, systemic inflammation was present at baseline in approximately 50% of individuals and was associated with several CV and kidney risk characteristics. The large proportion of participants with systemic inflammation in the groups with high CV risk shown here supports systemic inflammation as a plausible therapeutic target for the prevention of recurrent CV events.