Patrick Pogan faced up to four years behind bars or probation.
Jurors acquitted Pogan, 24, of assault and harassment in his 2008 encounter with pro-cycling activist Christopher Long. But Pogan was convicted of lying after a witness' video contradicted his account in a court document.
Pogan fought back tears and hugged relatives outside court after hearing his sentence - a lesser penalty than even his lawyer had sought. He thanked the police union and his lawyer as he left the courthouse.
Prosecutors pressed for jail time for Pogan, saying his falsehoods undermined faith in the criminal justice system. But defense lawyer Stuart London painted Pogan as a rookie who had made a paperwork mistake.
Pogan, a former emergency medical technician, said it had always been his dream to help people.
The case has highlighted the growing role of witness videos in law enforcement, and it spotlighted a history of conflict between the city's police and a group of pro-cycling demonstrators.
Pogan, then a rookie officer, was assigned to keep order and watch out for traffic violations as a loosely knit bike protest called Critical Mass passed through Times Square on July 25, 2008.
Participants and police had had a rocky relationship since more than 260 cyclists were arrested during what authorities saw as a chaotic Critical Mass ride shortly before the Republican National Convention in 2004.
Pogan said he told Long to stop to get ticketed for such infractions as taking his hands off his handlebars. Long kept going, and he testified he never heard any instruction to stop.
Pogan initially reported that Long steered into him and knocked him down, but a tourist's video showed the officer striding over to Long and shoving him off his bike. The video has garnered more than 2 million YouTube views.
Pogan testified that he was trying to protect himself and never meant to misrepresent what happened.
Long, who wasn't seriously hurt, was charged with attempted assault and other offenses. The charges later were dropped, and the city paid Long $65,000 to settle a lawsuit he filed.
Pogan resigned last year from the New York Police Department. Defense lawyer Stuart London declined to say whether Pogan, whose father is a retired NYPD detective, planned to speak at his sentencing.