People.com reports that Martha Jeanne is survived by her six grandchildren, including Harris. She also has 13 great-grandchildren, including Harris' twins, Gideon and Harper.
Harris won the 2014 Best Actor in a Musical Tony Award for his performance in Hedwig and the Angry Inch. He has performed on Broadway in Assassins, as well as Cabaret and Proof, and in the New York Philharmonic production of Company.
Harris, who has emceed the Tony Awards four times and the Emmys twice, will make his Oscars hosting debut in 2015. He has been honored with four Emmy Awards: three for his acclaimed hosting of the Tony Awards and another for his guest-starring role on "Glee."
Watch Harris' promotion for the Academy Awards here.
See Harris' tribute to his grandmother below.