Study GZRA is a master protocol that will support 2 independent studies, GZ01 and GZ02. Participants will be assigned to the appropriate study prior to randomization. The purpose of the studies is to evaluate the efficacy and safety of orforglipron in participants who have moderate-to-severe OSA and obesity or overweight. Study GZ01 will include participants who are unable or are unwilling to use PAP therapy. Study GZ02 will include participants who are on PAP therapy for at least 3 months at time of screening and plan to continue PAP therapy during the study.