American Gatlin qualified fastest in 9.77.
Jamaican Asafa Powell also secured his spot in the semi-finals after putting in a strong run to finish second behind Tyson Gay in his semi-final. Gay clocked 9.96 for top spot while Powell was just behind 9.97.
"Easy. Breezy," Gatlin said before going to warm down. The final was scheduled for 8:15 am Jamaica time (9:15 pm local time)
Gatlin, who won the 100 at the 2004 Olympics before serving a four-year suspension for doping, is unbeaten in 2015 and had the season-leading time of 9.74 heading into the championships. The 33-year-old American took bronze behind Bolt at the 2012 Olympics and silver at the 2013 world championships in Moscow.
The only time Bolt has failed to win gold in a sprint at a major championship since the 2008 Olympics was when he was disqualified for a false start in the heats of the 2011 world championships.