Crystal, who has hosted the Academy Awards for nine times, was also the first guest at the talk show in May 1992, reported Contactmusic.
Leno, 63, will step down from the show after the February 6 episode and TV personality Jimmy Fallon will succeed him as the host of the show.
Also, country music superstar Garth Brooks will perform on the final show.
"I am hoping we will enter into a new relationship with him and keep his home on NBC. I would love him to do specials with us and other shows he could host.