The jury of three men and three women deliberated for only 80 minutes before clearing Janikowski on the charges of drug possession and evidence tampering.
Police said Janikowski, a former Florida State all-American, poured the clear liquid from a water bottle onto a floor mat in the front seat of his car when an officer approached in a fraternity house parking lot in the early morning of June 21.
Janikowski faced up to five years in prison and possible deportation to his native Poland.
He is a resident alien and has a green card that permits him to work in the United States.
Janikowski testified Wednesday he did not know GHB was present when police arrested him and he wasn't even sure what GHB was.
The so-called date-rape drug can cause blackouts when mixed with alcohol.
Prosecutors dropped charges against Jay Hoffman, a 25-year-old Florida State business major who was arrested with Janikowski and testified on his behalf.
Prosecutors granted Hoffman immunity last July after he gave a sworn statement that he was not paying attention to what was happening in the front seat of the car.
Hoffman testified Wednesday that he did tell the prosecutor in July the drug belonged to him.
But he failed to say he passed the bottle up to the front seat from the back seat and asked his friend Jesse Harris to pour him a shot.
Under cross-examination, Hoffman told Assistant State Attorney Robin Freeman he never divulged that information because she never asked when she interviewed him a couple of weeks after the arrest.
Charges against Harris, a 20-year-old Florida State student, were referred to drug court.
Harris testified Wednesday he poured out the drug in the front seat of the car, not Janikowski.
Harris said he thought it was alcohol.
Hoffman testified that officers "were very short with me, they didn't want to listen to me."
He said he overheard one of the officers say: "You ain't going to get out of this one," apparently referring to Janikowski.
In closing arguments, Freeman challenged the credibility of Harris and Hoffman.
"His friends clearly have a stake in this case," she said. "The officers were doing their jobs that night.
"They don't have a stake in this case."
Defence lawyer Steven Dobson, however, argued the only reason Janikowski was prosecuted was because of his status.
"They wanted Mr. Janikowski so bad that they gave Mr. Hoffman immunity," he said.
He noted that all the police officers who testified in the case were still in the courtroom listening to the closing arguments even though they had been excused from the case.
He said they were there because "it's Sebastian Janikowski, that's why."
It's the second time in less than a year Janikowski, 23, has been on trial in the Leon County Courthouse.
A six-person jury needed only 50 minutes on June 13 to acquit Janikowski on a charge he offered a Tallahassee policeman $300 to release his roommate after an argument with a bouncer who wouldn't let him into a local nightclub.
In other testimony Wednesday, the campus police officer who arrested Janikowski said he had no formal training in identifying drugs.
In response to questions from Janikowski's lawyers, Florida State police officer C. Roy Wiley said he knew that until recent years GHB was a legal substance used by body builders to induce a deep sleep before awaking to work out.
Wiley said it also was used by partygoers.
Wiley testified Janikowski poured some liquid into the cap of the water bottle and handed it to the driver, then dumped the rest on the mat when Wiley flashed his badge.
The officer testified he did not know whether the bottle belonged to Janikowski or if Janikowski realized what the contents were.
"Is this case about drugs or is it about Mr. Janikowski?" asked another defence lawyer, Deeno Kitchen.
"It's about possession of GHB," Wiley replied.
Dobson told jurors, "What happened was a misunderstanding by a police officer who thought he saw something."
