Background: The use of skilled birth attendants (SBAs) is still a challenge in low- and middle-income countries, where it contributes significantly to maternal and neonatal morbidity and mortality. While Tanzania has made progress in maternal health, adolescents aged 15–19 remain disproportionately underserved in accessing SBA, which is critical for safe delivery. This study aims to assess the trends and predictors of SBA use among adolescent girls. Methods: This study analyzed nationally representative data from the Tanzania Demographic and Health Surveys (TDHS) conducted in 2004/05, 2010, 2015/16, and 2022. Trends in SBA use among adolescent mothers were assessed, and multivariable modified Poisson regression was used to determine predictors associated with SBA use in the 2022. Results were presented using adjusted prevalence ratio (APR) with a 95% confidence interval. Results: SBA use among adolescent mothers increased from 61.9% in 2004/05 to 85.3% in 2022. Despite this progress, disparities persisted across regions, with Dar es Salaam and Kilimanjaro maintaining near-universal coverage while others lagged. In 2022, adolescents were more likely to use SBA if they lived in urban areas (APR = 1.04), had secondary or higher education (APR = 1.10), came from wealthier households (APR = 1.08), attended four or more antenatal care visits (APR = 1.13), or had a partner with secondary or higher education (APR = 1.15). Rural residence and low educational attainment were associated with reduced SBA use. Conclusion: While SBA coverage among adolescents has improved in Tanzania, structural and social inequalities hinder equitable access. Strengthening adolescent-focused maternal health strategies, including improved ANC coverage, expanded education, and male partner engagement, is essential to address disparities and reduce maternal health risks among adolescent girls.