"They were obviously a couple or on a date," an insider told Us. "They were dancing, whispering, he had his hand on her back and shoulders and they were together all night."
Wilde tweeted the two were old pals -- and nothing more -- writing, "Cool it, honeybadgers. We are just friends and have been for years."
Timberlake, 30, split from girlfriend Jessica Biel on March 10 after a relationship lasting several years. Wilde, 26, filed for divorce from husband Tao Ruspoli on March 11 after eight years of marriage.
Wilde is starring in the upcoming sci-fi Western "Cowboys & Aliens," with Daniel Craig and Harrison Ford, while Timberlake stars with ex-GF Cameron Diaz in the dark comedy "Bad Teacher," and with Mila Kunis in "Friends with Benefits."