John K. Castle

Who is John K. Castle?

John K. Castle is Chairman and Chief Executive Officer of Castle Harlan, Inc. a private merchant bank and Branford Castle, Inc., which invests in small-to-medium sized private companies for the long term.

He is Chairman and Co-Publisher of Castle Connolly Medical Limited that prints Top Doctors and America’s Top Doctors. Two allied companies, Castle Connolly Graduate Medical Ltd and Publishing Works Ltd, publish study guides for doctors preparing for medical boards and newsletters focused on healthcare.

Castle started Castle Harlan in 1986. Prior to that he was President and Chief Executive Officer of Donaldson, Lufkin & Jenrette, Inc., and a director of the Equitable Life Assurance Society of the US.

In 1969, when he was Chairman of DLJ's Merchant Banking and Sprout Group, Castle was an early leader in using limited partnerships as a means for pension funds and other large institutions to invest private capital into companies.