We study the effects of two dimensions of teacher quality, subject knowledge and didactic skills, on student learning in francophone Sub-Saharan Africa. We use data from an international large-scale assessment in 14 countries that include individual-level information on student achievement and country-level averages of teacher subject knowledge and teacher didactic skills in reading and math. Exploiting variation between subjects in a student fixed-effects model, we find that teacher subject knowledge has a large positive effect on student achievement, whereas the effect of teacher didactic skills is comparatively small but imprecisely estimated. Differences in teacher subject knowledge account for 37 percent of the variation in average student achievement across countries.