This is an atlas of the developing rhesus macaque brain over the gestational age range (G)85 to G155 days, of a typically 165 day gestational term. This atlas is an update to the original ONPRC Fetal Macaque Brain Atlas. It consists of T2-weighted image templates, atlas labelmaps, and associated mid-cortical surfaces. These were generated from a mixed longitudinal and cross-sectional sample of 50 normally-developing rhesus macaque fetuses (28 female and 22 male), scanned in utero (105 scans). Template T2-weighted images were constructed for gestational ages G85, G97, G110, G122, G135, G147, and G155. Labelmaps and cortical mid-thickness models derived from the template images are also provided. Additional details are described in a manuscript that is currently under review, and the reference will be provided upon publication.