The Cetacean Welfare Assessment (C-Well), established a decade ago, has been applied globally more than 30 times across five cetacean species, with several facilities conducting repeated assessments. In this seminar, we describe the first results and detail how the framework has evolved over a 10-year period. We will summarise the updates made to the C-Well in line with the latest research, and describe how the approach has been adapted to non-cetacean species to form a series of “Zoo-Well” assessments.