Joseph F. Fitzpatrick Jr. (08 March 1932 – 11 July 2002 in Mobile, Alabama) was an American carcinologist.
Subsequently, he became an assistant professor at the Mississippi State University and at the Randolph-Macon Woman’s College.
In 1972, he was co-founder (with James Avault) of the International Association of Astacology in Hinterthal, Austria, an organisation which is devoted to the research of crayfish.
He was further fellow of the American Association for the Advancement of Science, and a member of Sigma Xi.
Fitzpatrick's main research field was the ecology and systematics of the crayfish in which he was recognized as one of the leading experts.