Arthur Collins, the ex-boyfriend of reality TV star Ferne McCann, threw the corrosive substance at revellers in Mangle E8 in Dalston on 17 April.
The 25-year-old admitted throwing the liquid but had claimed he believed it was a date rape drug.
He was convicted at Wood Green Crown Court. Andre Phoenix, who was accused of helping him, was found not guilty.
CCTV shown in court showed clubbers clutching their faces and running off the dancefloor as they were hit with the liquid.
Victims told the jury their skin began “blistering straight away” and described a burning smell. The liquid was later found to have a rating of pH1.
Collins told the court during the trial he had been at the club celebrating the news of Ms McCann’s pregnancy, which the couple had revealed to her family the previous day.
He was seen on CCTV getting into a confrontation with a group of men in the club before he sprayed liquid from a bottle over the crowd.
Collins, of Broxbourne, Hertfordshire, had claimed he had taken the bottle from that group and thought it was a date rape drug.
However, the jury found him guilty of five counts of GBH with intent, and nine counts of ABH against 14 people.
Collins will be sentenced on 19 December.