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West Africa continues to host a growing number of low and intermediate‐magnitude earthquakes (M2‐5) along its passive margins, and its continental interior. Earthquake activity in these regions raises the need to comprehend the causes and the tectonic controls of the seismicity. Unfortunately, such studies are rare. Here, we apply single‐station inversion techniques to constrain fourteen focal mechanisms, computed after compiling a set of high‐quality waveforms. We describe the connection between seismicity, the contemporary stress field, anthropogenic activity and Holocene fault scarps in the region. Our results indicate transpressive stresses acting on the inherited brittle structures in the passive margins. We also observe a compressive regime in the intracontinental failed rifts. We attribute the seismicity to the reactivation of "weak" faults in the Neoproterozoic and Mesozoic failed rifts, the passive transform structures, and the intracratonic Precambrian brittle shear zones. Plain Language Summary: Earthquakes have occurred in West Africa, in the interior and the edges of regions that host several brittle structures. The causes and the mechanisms of this seismicity have not been comprehensively investigated. Hence, the characteristics of the regional tectonics are not fully established. In this study, we resolve the properties of the source of earthquakes, and the regional stress field. Our description of the sources of earthquakes matches the geometry of inherited brittle shear zones and failed rifts. The results indicate a strong influence of transpressive stress transfers from the ocean to the passive margins of West Africa. In the continental interior, especially, the West African Belt, the stress is compressional in the E‐W direction, consistent with stress orientations in adjoining regions. An extensional earthquake is observed in Mali, within the Gourma failed rift. We find that the seismicity of West Africa and the variations of the stress can be explained by the combination of preexisting faults, plate forces, ocean‐continent stress transfer, and density heterogeneity across the geologic domains. Key Points: Improved constraints on stress regimes and stress orientations from inversion of new focal mechanisms of M < 5.5 earthquakesNew focal mechanisms obtained from classical and novel approach based on single station waveform inversionEarthquakes in West Africa are rupturing the passive margin faults, intracontinental failed rift faults, and brittle shear zones [ABSTRACT FROM AUTHOR]