This research explores the effects of supply chain alliance orientation on ambidextrous innovation and market performance with evidence from South Korean and US firms amid COVID-19. Three theories underpin the conceptual framework including the resource-based view, relational view, and ambidextrous innovation while psychosomatic items generate the variables: supply chain alliance orientation, exploration innovation, exploitation innovation, and market performance. Hypotheses are posed through a literature review. A multigroup analysis of 427 firms using MICOM with PLS-SEM is employed to reveal differences between South Korean and American companies. Here Korean firms generate ambidextrous innovation and market performance better than US firms. Mediation tests are also conducted. Implications are provided.