The school was secured at 12:03 p.m. and the lockdown was lifted 19 minutes later, Fort Lauderdale police spokeswoman Casey Liening said.
A 911 caller had claimed there was an armed person on campus, but gave the wrong school information and meant Lauderdale Lakes Middle school, Liening said.
As a precaution, officers searched Dillard anyway, Liening said.
Meanwhile, Lauderdale Lakes Middle also was locked down Friday, but for a report of a stabbing suspect in the neighborhood, not on the school property, Broward Sheriff’s spokeswoman Gina Carter said.
The school, at 3911 NW 30th Ave., has 885 kids enrolled in grades six through eight.
It was locked down from 11:45 a.m. for about an hour, the school district said.
The report of a stabbing turned out not to be true, Carter said.
Two of the other recent lockdown situations at Dillard High involved investigations of guns at the campus.
On Feb. 22, a 12-year-old boy was arrested and accused of trying to fire a BB gun at a counselor while on campus.
The student pointed the firearm and pulled the trigger twice, according to his arrest report. It wasn’t known if the gun was loaded or if it failed to fire. The teacher was not injured.
The student was hospitalized under Florida’s Baker Act. The law allows a person to be briefly, involuntarily hospitalized if he is considered mentally unstable or a danger to himself or others.
On Monday, a lockdown of the school, at 2501 NW 11th St., happened during an investigation of a possible student with a gun.
That situation drew dozens of Fort Lauderdale police officers, Broward Sheriff’s SWAT deputies and worried parents to the campus.
Officers left the school after they did not find a weapon.
There are 2,237 children enrolled in grades six through 12 who attend the middle school/high school complex, which is west of Interstate 95 and north of West Sunrise Boulevard.