According to the Chicago Manual of Style (17th ed.), interviews and personal messages may be cited in the footnotes alone, though in some cases you can add an entry to your bibliography as well.
Interviews rarely have a title, and the main focus is on identifying the interviewer and interviewee (listed first). If the interview has been published or is available in a collection of some sort, you can provide some additional information.
For unpublished interviews, cite as much information as is available:
1. Bertrand de Born (CEO, Schismatix Group), interview by Dante Lighthead, March 2, 2017.
2. Amish Killjoy, in discussion with the author, September 15, 2002.
de Born, Bertrand (CEO, Schismatix Group). Interviewed by Dante Lighthead. March 2, 2017.
Killjoy, Amish. Discussion with the author. September 15, 2002.
Let’s look at a couple of examples of how published interviews might be cited. First, here’s an interview shared on a blog:
1. Kim Jong-un, interview by Dennis Rodman, Embrace the Worm (blog), January 8, 2018, https://www.embracetheworm.wordpress.com/
Jong-un, Kim. Interviewed by Dennis Rodman. Embrace the Worm (blog). January 8, 2018. https://www.embracetheworm.wordpress.com/
Next, here’s an interview published as a journal article:
1. Michael Rode, “What’s New in the Recording Industry: Interview with Michael Rode,” by Jim Shure, The Right Focus 2, no. 5 (2017): 99-104.
Rode, Michael. “What’s New in the Recording Industry: Interview with Michael Rode.” By Jim Shure. The Right Focus 2, no. 5 (2017): 99-104.
In this case the title already indicates that this is an interview, so we’ve written “by Jim Shure” rather than “interview(ed) by Jim Shure.”
If your source has been published in a different format, don’t panic. Just adjust the format to meet your needs.
Personal messages don’t need to be cited in your bibliography. Most often you can just provide a name (where possible), a description (message, conversation, etc.), and a date:
1. Jane Birk, email message to the author, August 2, 2015.
For more information about how to cite interviews and messages, see sections 14.211-14.214 of the Chicago Manual of Style (17th ed.).