When citing audio commentary, treat the person or persons who provided the commentary as contributors to the work. Include the label “Audio commentary by” along with the name or names of those who participated in the commentary in the Contributor element of your entry:
Star Wars: The Last Jedi. Audio commentary by Rian Johnson, directed by Johnson, Walt Disney Studios / Buena Vista Home Entertainment / Lucasfilm, 2018.
If you are citing commentary for a TV episode, provide the names of commentators in the middle supplemental element after the title of the episode, since the audio commentary is for that episode, not the entire season:
“Peter.” Audio commentary by Blair Brown et al. Fringe: The Complete Second Season, season 2, episode 15, Warner Brothers Entertainment / Warner Home Video / Bad Robot, 2010, disc 4. Fringe: The Complete Series, Warner Brothers Entertainment / Warner Home Video, 2013.
If your discussion focuses primarily on the audio commentary, rather than on the film or television show, you may instead include the name of the commentator in the Author element:
Johnson, Rian, audio commentator. Star Wars: The Last Jedi. Directed by Johnson, Walt Disney Studios / Buena Vista Home Entertainment / Lucasfilm, 2018.
For more information about including contributors in the Author element, see section 5.40 in the MLA Handbook.
MLA Handbook. 9th ed., Modern Language Association of America, 2021.