4P/Faye (also known as Faye's Comet or Comet Faye) is a periodic Jupiter-family comet discovered in November 1843 by Hervé Faye at the Royal Observatory in Paris. It last came to perihelion (closest approach to the Sun) on May 29, 2014, and will next come to perihelion on September 8, 2021.
The comet was first observed by Faye on 23 November, but bad weather prevented its confirmation until the 25th. It was so faint that it had already passed perihelion about a month before its discovery, and only a close pass by the Earth had made it bright enough for discovery. Otto Wilhelm von Struve reported that the comet was visible to the naked eye at the end of November. It remained visible for smaller telescopes until 10 January 1844 and was finally lost to larger telescopes on 10 April 1844.
In 1844, Thomas James Henderson computed that the comet was a short period comet; by May, its period had been calculated to be 7.43 years. Urbain Le Verrier computed the positions for the 1851 apparition, predicting perihelion in April 1851. The comet was found close to his predicted position on 28 November 1850 by James Challis.
The comet was missed during its apparitions in 1903 and 1918 due to unfavorable observing circumstances. It reached a brightness of about the 9th magnitude in 2006.
The comet is estimated at about 3.5 km in diameter.