Understanding how sleep, sedentary behavior (SED), and physical activity (PA) (24-h movement profile) changes across pregnancy in individuals with prepregnancy overweight or obesity and how parity (previous births) impacts these changes can help inform interventions. In 155 participants, movement was measured using wrist-worn accelerometers, and sleep was self-reported in early (8-15 wk) and late (29-38 wk) pregnancy. The 24-hour movement profiles were analyzed using compositional analyses. Nulliparous participants (no previous births) spent 33.95%, 38.14%, 25.32%, and 2.58% of the 24-hour day in early pregnancy in sleep, SED, light-intensity PA, and moderate/vigorous-intensity PA, respectively. Multiparous participants (≥1 previous birth) spent 2.50 percentage points less in SED (mean log-ratio difference = -0.068; 95% confidence interval [CI], -0.129 to -0.009) and 2.73 percentage points more in light-intensity PA (mean log-ratio difference = 0.102; 95% CI, 0.035 to 0.180). From early to late pregnancy, participants decreased the proportion of the 24-hour day spent asleep by 1.67 percentage points (mean log-ratio difference = -0.050; 95% CI, -0.092 to -0.011) and increased light-intensity PA by 1.56 percentage points (mean log-ratio difference = 0.057; 95% CI, 0.003 to 0.108), with no change in other behaviors. Nulliparous and multiparous individuals with prepregnancy overweight or obesity both had high levels of SED, with no change across pregnancy, and may require interventions to reduce SED.