Although regular physical activity is recommended for osteoarthritis (OA) prevention, many adults fail to exercise consistently due to time constraints. We evaluated the association between the “weekend warrior” (WW) pattern, defined as accumulating the recommended amount of physical activity within one or two days per week, and incident OA. This prospective cohort study used data from the UK Biobank accelerometer substudy. A total of 83, 386 participants with valid 7-day wrist-worn accelerometer data were included. Participants were classified as inactive (< 150 min/week of moderate-to-vigorous physical activity [MVPA]), weekend warriors (≥ 150 min/week with ≥ 50% of MVPA accumulated within 1-2 days), or regularly active (≥ 150 min/week with ≥ 50% distributed across > 2 days). Sensitivity analyses were additionally conducted using progressively stricter MVPA concentration thresholds ranging from ≥ 55% to ≥ 95%. Incident OA was identified through linked health records. Cox proportional hazards models were applied to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Over a median follow-up of 7.9 years, 8, 130 incident OA cases were identified. Compared with inactive participants, both regularly active and weekend warrior patterns were associated with lower OA risk in fully adjusted models (HR = 0.889, 95% CI: 0.835-0.946, HR = 0.894, 95% CI: 0.850-0.941, respectively), and these inverse associations remained stable when using stricter MVPA concentration thresholds ranging from ≥ 55% to ≥ 90%. In contrast, compared with regularly active participants, weekend warrior participants did not show a statistically significant difference in OA risk (HR, 1.031; 95% CI, 0.968-1.099), even after further adjustment for total MVPA volume. Accumulating guideline-recommended MVPA within one to two days per week was associated with a lower risk of incident OA, comparable to regularly distributed physical activity. The weekend warrior pattern may represent a practical option for OA prevention among time-constrained adults.