William Owen moved to London in 1786 and was apprenticed for seven years to the coach-painter Charles Catton. He was encouraged by Sir Joshua Reynolds to enter the Royal Academy Schools, which he did in 1791. His first work was exhibited at the Royal Academy in the following year and he continued to exhibit nearly every year until his death.
Owen's work comprised mainly portraits. In 1810, he was appointed portrait painter to the Prince of Wales; the prince promised to sit for Owen but never did.