The 34-year-old "Dirrty" hitmaker hit the stage in the Hamptons event at The Creeks, the estate of billionaire philanthropist Ron Perelman.
She performed tracks including "Lady Marmalade" and "Ain't No Other Man" for guests including Jack Nicholson, Mary-Kate Olsen, comedian Jimmy Fallon, US presidential candidate Chris Christie and New York City Mayor Bill de Blasio, reported People magazine.
During the performance, Aguilera decided to give a special shout out to her man as they prepared to mark their baby girl Summer Rain's birthday, telling the crowd, "This is a special weekend. It's my daughter's first birthday."
The couple became engaged on Valentine's Day last year.
Aguilera is also mother to seven-year-old son Max, from her first marriage to Jordan Bratman, which ended in 2011.