BACKGROUND Digital platforms increasingly organize work through algorithmic management (AM), using automated systems to allocate tasks, monitor performance, and enforce disciplinary actions. These digitally mediated work environments may shape workers’ mental health, yet quantitative evidence on these associations remains limited. OBJECTIVE This study examines the association between algorithmic management and mental health among digital platform workers in Sweden and explores whether these associations differ across platform work settings and dimensions of algorithmic control. METHODS We conducted a cross-sectional study using data from 734 digital platform workers participating in the GIG-HEALTH cohort (2023–2025). Algorithmic management was measured using a multidimensional index of 12 items capturing exposure to task direction, performance evaluation, and disciplinary mechanisms. Outcomes included psychological distress, burnout, sleep problems, and general health status. Associations were estimated using Poisson regression models with robust variance, adjusting for sociodemographic and work-related confounders. Analyses were stratified by platform work type (location-based vs web-based); additional analyses examined specific dimensions of algorithmic management. RESULTS Higher exposure to algorithmic management was consistently associated with a higher prevalence of adverse mental health outcomes. Greater exposure to AM by 0.1 index units was associated with increased prevalence of psychological distress (Prevalence Ratio [PR]=1.12, 95% CI 1.06–1.19), burnout (PR=1.07, 95% CI 1.02–1.13), sleep problems (PR=1.06, 95% CI 1.02–1.10), and poor general health (PR=1.12, 95% CI 1.01–1.23). Associations were more pronounced among location-based platform workers compared to web-based workers. Among AM dimensions, disciplinary mechanisms showed the strongest associations with adverse mental health outcomes. CONCLUSIONS Algorithmic management is associated with adverse mental health outcomes among platform workers, particularly in location-based work settings and in relation to disciplinary forms of control. These findings highlight the importance of considering digitally mediated work organization as a determinant of mental health in platform-based labor and suggest the need for greater attention to how algorithmic systems are designed and deployed.