The 59-year-old will be out of prison in six weeks since he has already spent several months in custody, his lawyer told news agencies after the court verdict on Thursday.
The victim, a father of two, was left in a coma for nine months and subsequently died at the age of 43, after being punched by the bouncer at Rooftop 42, an upmarket bar on Geneva's Rue du Rhône in September 2015.
The victim, who was drunk, had insulted the bouncer after he asked him to leave the bar, reported news agencies.
The bouncer, a former kickboxing champion, then used his weaker hand to punch the victim in the head three times, heard the court.
The victim fell to the ground and hit his head, suffering irreversible brain injury that put him into a coma.
The court found that the bouncer did not intend to kill the victim but that he violated his obligation to act with care in making the victim leave the bar.
Afterwards the bouncer called the emergency services in tears and admitted what he had done.
The court handed down a three-year sentence, half of which is suspended, and ordered him to undergo psychiatric treatment.
He must also pay 60,000 francs damages to the victim's widow and 40,000 to each of his two daughters.