HR diagrams of the ULLYSES SMC and LMC targets. Stellar parameters are based on contemporary literature from Table B.2 (filled symbols) or spectral type calibrations (open symbols). For known binary and multiple systems, only primaries are indicated. Calibrations used are Doran et al. (2013) for O-type stars in both galaxies, Dufton et al. (2019), Trundle et al. (2004), and Trundle & Lennon (2005) for SMC B-type stars, and Dufton et al. (2018), Garland et al. (2017), McEvoy et al. (2015), and Urbaneja et al. (2017) for LMC B-type stars. Evolutionary tracks (solid lines) and isochrones (dotted lines) for non-rotating massive stars at 0.5 Z_⊙ and 0.2 Z_⊙ are from Brott et al. (2011), supplemented by tracks for very massive stars in the LMC from Köhler et al. (2015).