Agatharesinol (AR) and sequirin C (SC) are representative norlignans derived from Cryptomeria japonica that exhibit antioxidant properties. However, their biological applications in animal systems remain unclear. This study evaluated the effects of AR and SC supplementation during in vitro maturation (IVM) on porcine oocyte maturation, fertilization, and embryonic development in vitro. Cumulus-oocyte complexes were cultured with AR or SC at various concentrations, followed by in vitro fertilization and embryo culture. Both compounds improved maturation, fertilization, and blastocyst formation rates compared with the controls. Optimal concentrations were 0.5 and 5 µM for AR and SC, respectively. Therefore, AR or SC supplementation during IVM improved oocyte maturation and was associated with improved subsequent embryonic development, highlighting the potential of norlignan-type compounds as novel bioactive agents for improving in vitro embryo production.