Background: Owing to safety concerns, individuals with chronic kidney disease (CKD), particularly those at more advanced stages, have been systematically underrepresented in randomised controlled trials (RCTs) of blood pressure (BP)-lowering treatment, leading to a persistent paucity of evidence for cardiovascular risk management in this high-risk group. We sought to investigate the effect of BP-lowering treatment on the risk of major cardiovascular disease and death across the full spectrum of CKD stages, and by key clinical subgroups.Methods: We conducted a one-stage individual participant data meta-analysis of RCTs in which participants were randomised to a BP-lowering therapy—single or multiple agents or an intensive regimen—versus a comparator (placebo, active agent, or a less intensive regimen). RCTs with at least 1000 person-years of follow-up per arm, with baseline BP and creatinine measurements, and time-to-event outcomes were eligible; those with unclear randomisation procedures or restricted to heart failure or acute care settings were excluded. Participants with a documented history of heart failure or extreme creatinine values were excluded. The primary outcome was major cardiovascular events, defined as a composite of fatal or non-fatal stroke, ischaemic heart disease, or hospitalisation for, or death from, heart failure. Relative treatment effects were estimated using a stratified Cox proportional hazards model. Heterogeneity of treatment effects was evaluated across prespecified subgroups defined by CKD status, CKD stage (1–5), diabetes, proteinuria, and baseline BP. Stratified network meta-analysis was performed to examine whether treatment effects differed by defined subgroups within each of five principal antihypertensive drug classes.Findings: A total of 285,124 participants from 46 randomised trials met the eligibility criteria; 41.5% were women, 20.7% had CKD at baseline, and 22.8% had type 2 diabetes. During a median follow up of 4.4 years (IQR 3.2–5.1), a 5 mm Hg achieved reduction in systolic BP reduced the risk of major cardiovascular disease by approximately 10% in individuals both with and without CKD (with CKD: HR 0.91 [95% CI 0.87–0.94]; without CKD: HR 0.90 [0.88–0.93], Pinteraction >0.99 ). Furthermore, these observed relative risk reductions were consistent across all CKD stages, including severe stages 4–5 (Pinteraction > 0.99). Similar treatment effects were observed by proteinuria status and across BP categories, down to <120/70 mm Hg. However, the relative treatment effect in individuals with CKD was notably attenuated among those with coexisting diabetes (HR 0.96 [95% 72 CI 0.90–1.02]) compared with those without (HR 0.88 [95% CI 0.84–0.93]; Pinteraction = 0.04). The stratified analysis within each drug class showed that the class-specific effects of antihypertensive agents versus placebo on cardiovascular disease risk remained unchanged across the investigated subgroups.Interpretation: In the context of cardiovascular risk reduction, the relative benefit of BP lowering in patients with CKD is comparable to that in individuals without CKD, with consistent efficacy across all CKD stages, BP thresholds, and proteinuria status. Notably, however, this relative benefit is attenuated in patients with CKD and concomitant diabetes, underscoring the requirement for adapted therapeutic strategies in this high-risk subgroup. Moreover, the class-specific effects of principal antihypertensives in CKD mirror those observed in the broader population, independent of CKD 82 stage or proteinuria status. Funding: British Heart Foundation