Thomas Denny Sanford (born December 23, 1935, in Saint Paul)[1] is a South Dakota businessman and philanthropist.

He is the founder of First Premier Bank and the chairman and chief executive officer of its holding company, United National.

He later became a student at the University of Minnesota, intending to become a doctor, but struggled with chemistry and switched majors, eventually graduating with a degree in psychology in 1958.

In 2007, Sanford paid $4.5 million as part of a settlement with the New York Attorney General that alleged deceptive practices in marketing.

Premier Bank offered a credit card with a 79.9% interest rate and a $300 limit, an amount cited by Senator Bernie Sanders as an example of "extortion and loan sharking".