According to TVLine.com, the show's producers, including series co-creator Ryan Murphy, offered Colfer the opportunity. No additional details on the episode have been released.
Following the announcement, Colfer tweeted, "Thanks so much for the trend! Wish me luck! =) #gulp"
Colfer wrote the screenplay for the 2012 indie film "Struck By Lightning," which he also produced and starred in, and the "Land of Stories" children's book series.
Click here for more information on the show's 100th episode, which airs March 18.