Abstract Background The use of modern contraception has increased in much of sub-Saharan Africa (SSA). However, the extent to which changes have occurred across the wealth spectrum among adolescents is not well known. We examine poor-rich gaps in demand for family planning satisfied by modern methods (DFPSm) among sexually active adolescent girls and young women (AGYW) using data from national household surveys. Methods We used recent Demographic and Health Surveys and Multiple Indicator Cluster Surveys to describe levels of wealth-related inequalities in DFPSm among sexually active AGYW using an asset index as an indicator of wealth. Further, we used data from countries with more than one survey conducted from 2000 to assess DFPSm trends. We fitted linear models to estimate annual average rate of change (AARC) by country. We fitted random effects regression models to estimate regional AARC in DFPSm. All analysis were stratified by marital status. Results Overall, there was significant wealth-related disparities in DFPSm in West Africa only (17.8 percentage points (pp)) among married AGYW. The disparities were significant in 5 out of 10 countries in Eastern, 2 out of 6 in Central, and 7 out of 12 in West among married AGYW and in 2 out of 6 in Central and 2 out of 9 in West Africa among unmarried AGYW. Overall, DFPSm among married AGYW increased over time in both poorest (AARC = 1.6%, p < 0.001) and richest (AARC = 1.4%, p < 0.001) households and among unmarried AGYW from poorest households (AARC = 0.8%, p = 0.045). DPFSm increased over time among married and unmarried AGYW from poorest households in Eastern (AARC = 2.4%, p < 0.001) and Southern sub-regions (AARC = 2.1%, p = 0.030) respectively. Rwanda and Liberia had the largest increases in DPFSm among married AGYW from poorest (AARC = 5.2%, p < 0.001) and richest (AARC = 5.3%, p < 0.001) households respectively. There were decreasing DFPSm trends among both married (AARC = − 1.7%, p < 0.001) and unmarried (AARC = − 4.7%, p < 0.001) AGYW from poorest households in Mozambique. Conclusion Despite rapid improvements in DFPSm among married AGYW from the poorest households in many SSA countries there have been only modest reductions in wealth-related inequalities. Significant inequalities remain, especially among married AGYW. DFPSm stalled in most sub-regions among unmarried AGYW.