Police were called to the campus after a fire alarm went off around 12:20 a.m. Arriving officers found 30-year-old James Oliver Seevakumaran dead from what appeared to be a self-inflicted gunshot wound to the head.
Police said they found an assault weapon and improvised explosive devices at the scene. The university canceled morning classes and evacuated about 500 students as a sheriff's bomb squad examined the devices.
University spokesman Grant Heston said normal campus operations resumed around noon after the makeshift devices were taken away from the dorm, which remained closed.
Grant Hernandez, a sophomore from Orlando who also is a resident at the dorm, said he woke up sometime after midnight when police were evacuating the building.
"All we saw were people running, and they were not telling us what was going on," Hernandez said. "We were left unsure of things. It wasn't till about 6 o'clock that we got more information and a clearer picture of what was going on."
At a news conference, officials said it appeared that Seevakumaran, a business major, had planned a wider attack. He pulled a gun on another student, who called police. Police say he killed himself moments later as officers were responding.
"We think the rapid response of law enforcement may have changed his ability to think quickly on his feet," said University of Central Florida Police Chief Richard Beary.
Police found notes and writings that confirmed Seevakumaran was planning an attack.
Authorities said he was never seen by counseling at the university. According to Florida records, his only adult arrest in the state was in 2006 for driving with a suspended license. He pleaded no contest. He was fined $105 and assigned court costs of $223.
The Associated Press contributed to this report.