O’Sha began his union advocacy in 2016 as a Shop Steward for TWU Local 556, the union representing Southwest Airlines flight attendants. He expanded his leadership involvement by serving as the International TWU State Conference Chair for Maryland, Washington, D.C., and Virginia, focusing on political and legislative affairs. In 2024, O’Sha was elected to the Executive Board of his local union as a Member-at-Large, representing more than 23,000 members. That same year, he was also appointed Treasurer for Pride At Work.