A White House pool report said Obama and the first lady had dinner with several guests Saturday night at Washington's Restaurant Nora, ahead of the Michelle Obama's birthday Sunday.
The presidential couple spent nearly four hours at the restaurant, which an unidentified White House aide said the couple has not visited since Obama took office.
As Obama and his wife left the eatery, nearly 50 people gathered outside sang "Happy Birthday" for the first lady, earning waves from the couple.
Among the guests at the surprise dinner were Michelle Obama's mother, Marian Robinson; U.S. Attorney General Eric Holder and his wife, Sharon Malone; the president's special adviser, Valerie Jarrett; the first lady's chief of staff, Susan Sher; and other officials and friends.
The White House said the Obamas' daughters, Malia and Sasha, were not in attendance.