The Light welterweight competition was the median weight class featured at the 2009 World Amateur Boxing Championships, and was held at the Mediolanum Forum. Welterweights were limited to a maximum of 64 kilograms in body mass.
| Gold | Roniel Iglesias |
| Silver | Frankie Gomez |
| Bronze | Uranchimegiin Mönkh-Erdene |
| Gyula Káté |
Roniel Iglesias (champion)
Gyula Káté (semifinals)
Masatsugu Kawachi (first round)
Eduard Hambardzumyan (second round)
Alexis Vastine (third round)
Driss Moussaid (third round)