Cpl. Kelsey De Santis said she was honored that the singer and actor accepted her invitation via YouTube video to the Marine Corps Ball in Richmond.
De Santis said Tuesday on the "Today" show and "Good Morning America" that the experience was wonderful.
She said she and Timberlake had one dance, and the rest of the time they enjoyed mingling among the crowd.
"He had a smile on his face the entire time and taking pictures of people, and we were talking, shaking hands," she said on ABC's "Good Morning America." "It was great."
De Santis said both she and Timberlake came away from the event with a renewed appreciation of the men and women who serve in the U.S. military.
Timberlake said on his website after the event that it was "one of the most moving evenings I've ever had" and that people should take the opportunity to thank service members.
Any advice to Scott Moore, the Marine who invited Timberlake's "Friends With Benefits" co-star Mila Kunis to his ball in Greenville, N.C., this weekend?
"I don't think he needs it with the video he came out with," said De Santis, who noted Moore apparently doesn't lack confidence.
"He'll have a great time, just like I did," she said in an interview on NBC's "Today" show.