DeGeneres, who played a nurse in a sick room scene of the hit musical revival opposite stars Sean Hayes and Kristin Chenoweth, was in town to promote the upcoming season of her daytime talk show. She had delivered David Letterman's "Top 10 List" at a taping of his late-night talk show earlier in the day.
DeGeneres recently resigned her post as judge on "American Idol."
To view a photo of DeGeneres cracking up the Promises stars, look below:
Michael Rozman/Warner Bros.