Attempts in the UK to regulate the sharing and use of health data for secondary purposes such as research have been dogged by controversy and failure. This article considers health data stewardship as a response to these challenges. It develops a normative understanding of the concept through an examination of stewardship in a variety of contexts. This leads to a definition of health data stewardship which encapsulates the necessary constituent elements that focus group participants viewed as crucial to an accountable health data sharing scheme in which they could place their trust. It examines two potential mechanisms for facilitating health data stewardship, the data trust and the data cooperative, arguing that whichever regulatory mechanism is adopted must incorporate mechanisms responsive to citizens’ requirements for accountable stewardship of their data. Without this, their wishes, and societal aims of improving health through research using comprehensive data sets may be unachievable.