Background <p>This study investigates whether sedentary behavior patterns—such as inter-day variability and intraday accumulation patterns—are associated with dynamic glycemic outcomes, an association not previously examined in women with overweight and obesity.</p> Method <p>Fifteen participants (age: 20.6 ± 1.0&#xa0;years; BMI: 28.1 ± 2.2&#xa0;kg/m²) underwent simultaneous accelerometer and continuous glucose monitoring. Associations between sedentary behavior patterns (including breaks in sitting, time spent in ≥ 30-min sedentary bouts, and median sedentary bout duration), and their inter-day variability computed as the coefficient of variation (CV), and overall glycemic outcomes were examined using linear regression. Intraday associations between daytime sedentary behavior patterns and time-matched daytime and subsequent nighttime glycemic outcomes were examined using linear mixed models.</p> Results <p>Data from 144 person-days were analyzed. After adjustment for total sitting time and relevant covariates, a higher inter-day variability in time spent in ≥ 30-min sedentary bouts was associated with a higher percentage of time spent within the target glucose range (<i>β</i> = 1.281% 95% CI [0.107, 2.454], <i>P</i> = 0.037). A longer intraday median sedentary bout duration was associated with an increased nighttime CV of glucose (<i>β</i> = 0.13% 95% CI [0.012, 0.248], <i>P</i> = 0.031).</p> Conclusion <p>Women with overweight and obesity who alternated between days with more prolonged (≥ 30&#xa0;min) sitting and days with less, and who had a shorter median sedentary bout duration, showed more favorable glycemic outcomes.</p>