  Using both time-dependent density functional theory (TDDFT) and the
``single-shot" $GW$ plus Bethe-Salpeter equation ($GW$-BSE) approach, we
compute optical band gaps and optical absorption spectra from first principles
for eight common binary and ternary closed-shell metal oxides (MgO,
Al$_2$O$_3$, CaO, TiO$_2$, Cu$_2$O, ZnO, BaSnO$_3$, and BiVO$_4$), based on the
non-empirical Wannier-localized optimally-tuned screened range-separated hybrid
functional. Overall, we find excellent agreement between our TDDFT and $GW$-BSE
results and experiment, with a mean absolute error less than 0.4 eV, including
for Cu$_2$O and ZnO, traditionally considered to be challenging for both
methods.
