The accused, Devender Singh, a resident of Louisiana, admitted before US District Judge Stanley Chesler in Newark federal court to an information charging him with abusive sexual contact, US Attorney Paul Fishman said.
The charge carries a maximum potential penalty of two years in prison and a USD 250,000 fine.
He is scheduled to be sentenced in October.
According to the documents filed in the case, Singh was seated next to a woman who occupied a window seat on a United Airlines flight from Houston to Newark.
After pushing Singh off of her and telling him to get away, the woman complained to a flight crew member about the incident and asked that the police be present when the plane landed.
The federal government has exclusive jurisdiction over all sexual abuse cases that occur on aircraft in flight in the US.