Charles Thomas Kowal (born November 8 1940) is an American astronomer.

He discovered two moons of Jupiter: Leda in 1974 and Themisto in 1975, although the latter was lost and not rediscovered until 2000.

He also discovered the unusual asteroid/comet 2060 Chiron in 1977.

Besides Chiron he discovered or co-discovered a number of other asteroids, including notably the Aten asteroid 2340 Hathor ; the Apollo asteroids 1981 Midas, 2063 Bacchus, 2102 Tantalus , and (5660) 1974 MA ; the Amor asteroids (4596) 1981 QB and (4688) 1980 WF ; and the Trojan asteroids 2241 Alcathous and 2594 Acamas .

He also discovered many supernovas in other galaxies, and discovered or co-discovered some comets, including periodic comets 99P/Kowal , 104P/Kowal , 134P/Kowal-Vavrova , 143P/Kowal-Mrkos , 158P/Kowal-LINEAR (and Chiron has the cometary designation 95P/Chiron).