Erythropoiesis requires a combination of ubiquitous and tissue-specific transcription factors. Here, through DNA affinity purification followed by mass spectrometry, we have identified the widely expressed protein MAZ (Myc-associated zinc finger) as a transcription factor that binds to the promoter of the erythroid-specific human α-globin gene. Genome-wide mapping in primary human erythroid cells revealed that MAZ also occupies active promoters as well as GATA1-bound enhancer elements of key erythroid genes. Consistent with an important role during erythropoiesis, knockdown of MAZ in primary human erythroid cells impairs erythroid differentiation, and genetic variants in the MAZ locus are associated with clinically important human erythroid traits. Taken together, these findings reveal the Zinc-finger transcription factor MAZ to be a previously unrecognised regulator of the erythroid differentiation program.