The singer Justin Timberlake pleaded guilty on Friday to driving while impaired, resolving a case that began with his June arrest on drunken-driving charges in the Hamptons.

As part of his plea, Mr. Timberlake agreed to pay a $500 fine and serve 25 hours of community service for a charity of his choosing. He also agreed to a 90-day suspension of his driver’s license in New York.

The singer, who was originally charged with the more serious crime of driving while intoxicated, entered the plea during an appearance at a 30-seat courthouse in the village of Sag Harbor. He wore a black cardigan and khaki slacks, with a double strand of pearls peeking out from beneath a dark T-shirt.

Speaking to reporters outside the courthouse after the hearing, Mr. Timberlake urged people following the case to learn from his mistake.

“Many of you have probably been covering me for a lot of my life, and as you may know, I try to hold myself to a very high standard, for myself, and this was not that,” he said.

The arrest occurred in the early hours of June 18, when a Sag Harbor police officer pulled over a new-model BMW that was driving erratically.