He was in the United States Navy during World War II, from 1943 to 1946, achieving the rank of Lieutenant Commander.

[1] On June 4, 1963, Phillips was nominated by President John F. Kennedy to a seat on the United States Court of Appeals for the Sixth Circuit vacated by Judge John Donelson Martin Sr. Phillips was confirmed by the United States Senate on June 28, 1963, and received his commission on July 3, 1963.

He served as Chief Judge from 1969 to 1979, assuming senior status on January 15, 1979 and serving in that capacity until his death on August 3, 1985, in London, England, due to injuries suffered from being struck by the driver of a vehicle while crossing a street in London.

[1][2] In 1986, the United States Court of Appeals for the Sixth Circuit named its Nashville satellite library after Judge Phillips in recognition of his lifelong commitment to legal scholarship.

[2] The Harry Phillips American Inn of Court (AIC) was founded in 1990 in Nashville, Tennessee.