Brucella ceti has been recovered from a number species of cetaceans worldwide over the last 25 yr. Here we report, for the first time, the recovery of B. ceti from a Risso’s dolphin Grampus griseus and a killer whale Orcinus orca . Recovery from an abdominal mass in the dolphin provides further evidence of the systemic pathogenic potential for B. ceti infection in cetaceans. The isolation of B. ceti ST23 (porpoise cluster) from a killer whale from a group known to eat other marine mammals raises the possibility of infection via ingestion. This report takes the number of cetacean species in UK coastal waters from which B. ceti has been isolated to 11 and highlights the value of routine, comprehensive and specific screening for significant pathogens such as Brucella sp. by strandings networks.