Philip Herbert Cowell FRS (7 August 1870, Calcutta – 6 June 1949) was a British astronomer.
Philip Herbert Cowell was born in Calcutta, India and educated at Eton and Trinity College, Cambridge. He became second chief assistant at the Royal Greenwich Observatory in 1896 and later became the Superintendent of HM Nautical Almanac Office during 1910–1930. He worked on celestial mechanics, and orbits of comets and minor planets in particular. He also carefully studied the discrepancy that then existed between the theory and observation of the position of the Moon.
He was elected a Fellow of the Royal Society on 3 May 1906. He won the Gold Medal of the Royal Astronomical Society in 1911.
In 1909, he discovered 4358 Lynn, a 10-kilometer sized main-belt asteroid and member of the Eunomia.
In 1910, Cowell and Andrew Crommelin jointly received the Prix Jules Janssen, the highest award of the Société astronomique de France, the French astronomical society.
He died in Aldeburgh, Suffolk. The main-belt asteroid 1898 Cowell is named after him.