This paper investigates how professional learning of teachers might be improved by two key factors: distributed leadership and teacher agency. Designed as a cross-sectional survey, this study used data from a total of 283 teachers working in a mix of public primary, secondary, and high schools across nine provinces in the eastern, central, and western regions of Turkey. The results showed a very small direct relationship between distributed leadership and teacher professional learning, while teacher agency played a significant mediation role with a moderate effect size. These results extend prior research by providing evidence that distributed leadership may not have a large direct influence on teacher learning; instead, its influence is rather indirect through improving teachers' sense of agency.