Portrait of Dr. Albert C Getchell

Thomas Cowperthwait Eakins (; July 25, 1844 – June 25, 1916) was an American realist painter, photographer, sculptor, and fine arts educator. He is widely acknowledged to be one of the most important American artists.

For the length of his professional career, from the early 1870s until his health began to fail some 40 years later, Eakins worked exactingly from life, choosing as his subject the people of his hometown of Philadelphia. He painted several hundred portraits, usually of friends, family members, or prominent people in the arts, sciences, medicine, and clergy. Taken en masse, the portraits offer an overview of the intellectual life of contemporary Philadelphia of the late 19th and early 20th centuries.

In addition, Eakins produced a number of large paintings set in the offices, streets, parks, rivers, arenas, and surgical amphitheaters of his city. These active outdoor venues allowed him to paint the subject that most inspired him: the nude or lightly clad figure in motion. In the process, he could model the forms of the body in full sunlight, and create images of deep space utilizing his studies in perspective. Eakins took keen interest in new motion photography, a field in which he is now seen as an innovator.

Eakins was also an educator, and his instruction was a highly influential presence in American art. The difficulties he encountered as an artist were seeking to paint portraits and figures realistically as behavioral and sexual scandals truncated his success and challenged his reputation.

Eakins was a controversial figure whose work received little recognition during his lifetime. Since his death, he has been celebrated by American art historians as "the strongest, most profound realist in nineteenth- and early-twentieth-century American art".