Thomas Phillips (October 18, 1770 - April 20, 1845) was an English portrait and subject painter.

He was born at Dudley in Warwickshire. Having acquired the art of glass-painting in Birmingham, he visited London in 1790 with an introduction to Benjamin West, who found him employment on the windows in St George's Chapel at Windsor. In 1792 Phillips painted a view of Windsor Castle, and in the next two years he exhibited the "Death of Talbot, Earl of Shrewsbury, at the Battle of Castillon," "Ruth and Naomi," "Elijah restoring the Widow's Son," "Cupid disarmed by Euphrosyne," and other pictures. After 1796, however, he mainly confined himself to portrait-painting. It was not long before he became the chosen painter of men of genius and talent, notwithstanding the rivalry of Hoppner, Owen, Jackson and Lawrence; and he left behind portraits of nearly all the illustrious characters of his day.

In 1804 he was elected associate and in 1808 member of the Royal Academy. In 1824 Phillips succeeded Fuseli as professor of painting to the Royal Academy, an office which he held till 1832. During this period he delivered ten Lectures on the History and Principles of Painting, which were published in 1833.