Sealtest Dairy is a Good Humor-Breyers brand for dairy products. Formerly a division of National Dairy Products Corporation (precursor to Kraft Foods, Inc.) of Delaware, it produced milk, cream, ice cream, and lemonade. The Sealtest brand was also later used by various companies in Canada under license (now held by Agropur).

ealtest had milk and ice cream plants across the midwestern and northeastern part of the United States, with large operations in Chicago, Milwaukee, Cleveland, La Crosse, Wisconsin, Huntington, Indiana, Rockford, Illinois, Philadelphia, Baltimore and New York City. Its Mid-South operations were based in Nashville.

The Milwaukee operation was purchased from a family-owned dairy operation, Luick Dairy, in the late 1940s or after. The Sealtest brand was originally a franchise, much like the ‘Quality Chekd’ dairy brand – local milk bottlers bought the rights to the Sealtest name in their market areas. Luick and presumably all the other franchisees were bought up by National Dairy Co.