Clayton comfortably defended the under-20 title she won in Nairobi last year in a time of 10.95 seconds, with her schoolmate Serena Cole edging American Shawnti Jackson for silver at Cali's Pascual Guerrero Stadium.
"Coming out, my mindset wasn't about a personal best or championship record, it was to defend my title," Clayton told the World Athletics website.
"I didn't feel any pressure."
Shelly-Ann Fraser-Pryce, Shericka Jackson and Elaine Thompson-Herah swept the 100m podium for Jamaica at the senior World Championships in Oregon last month, having done the same in a different order at last year's Tokyo Olympics.
American Jackson, is the daughter of former world champion 400m hurdler Bershawn.