It has been stated in numerous articles, websites, and television shows that Bert and Ernie from Sesame Street were named after two characters from the film It's a Wonderful Life, Bert the policeman and Ernie the cab driver. The statement often surfaces around Christmas, or in filler "trivia" columns in newspapers.
There has never been any official confirmation of this statement. On the contrary, most sources from the Henson company have claimed it to be merely a coincidence.
A more in-depth response was given by Jerry Juhl, writing to The San Francisco Chronicle to correct the "Annual Xmas Quiz" from December 27, 1999:
The show referenced the persistent rumor in the 1996 special Elmo Saves Christmas. In one scene, Ernie and Bert walk by a TV set, which is playing the movie. The pair are surprised by the following dialogue: "Bert! Ernie! What's the matter with you two guys? You were here on my wedding night!"
The rumor has been reinforced by various sources, including Sesame Workshop, through their 35th anniversary trivia quiz on Sesamestreet.org, the Sesame Street Live Facebook page, and even by Sesame Workshop CEO Gary Knell.