5145 Pholus /ˈfoʊləs/ is an eccentric centaur in the outer Solar System, approximately 180 kilometers (110 miles) in diameter, that crosses the orbit of both Saturn and Neptune.

It was discovered on 9 January 1992 by American astronomer David Rabinowitz (uncredited) of UA's Spacewatch survey at the Kitt Peak National Observatory in Arizona, United States.

[5] It is a Saturn-, Uranus- and Neptune-crosser, crossing the orbits of these giant planets at a mean distance of 9.6, 11.9, and 30.1 AU from the Sun, respectively.

Pholus was discovered by David Rabinowitz (not officially credited), working with the Spacewatch program, at Kitt Peak National Observatory on 9 January 1992.

The discovery was announced by James Scotti on 23 January 1992 in an IAU Circular (IAUC 5434) of the Central Bureau for Astronomical Telegrams.

[2] A first precovery was taken at the Australian Siding Spring Observatory in 1977, extending the centaur's observation arc by 15 years prior to its discovery.

[21] A symbol derived from that for 2060 Chiron, U+2BDB ⯛ PHOLUS (), was devised in the late 1990s by German astrologer Robert von Heeren.

[11][12] Polarimetric observations with ESO's Very Large Telescope in 2007 and 2008, revealed noticeable negative polarization at certain phase angles, distinctly different from that of trans-Neptunian objects.