Tropical coral reefs are prominent marine landscapes often found surrounding volcanic islands, where interactions between corals and volcanic eruptions are inevitable. Knowledge of volcanic tephra–coral interactions, however, remains limited and, where reported, has largely focused on the detrimental physical impacts on reefs from large-scale eruptions. To investigate the physiological response of corals to tephra and associated seawater trace metal interactions, multiple controlled culture experiments were conducted. Symbiotic corals, primarily the model species Stylophora pistillata, were exposed to pristine and weathered tephra collected after the 2021 eruption of La Soufrière volcano, St. Vincent. Tephra samples were geochemically characterised, and their trace metal leaching potential was quantified using ICP-MS. All tephra samples released essential micronutrients, particularly Mn, into seawater, with pristine tephra exhibiting the highest leaching rates. Tephra exposure resulted in trace metal bioaccumulation, altered internal metal partitioning within corals, enhanced photophysiological performance, and increased skeletal growth.