Mackenzie Hollister is Nikki's arch rival and Gary's love interest appearing in the 2003 Warner Bros. Animation series, The Dork Diaries. She has long blond hair and deep blue eyes. Her main outfit (as shown in the television series) is composed of: a pink long sleeved shirt, pink skirt, black pantyhose and red dress shoes. She is voiced by Jennifer Hale (who also voices Sam Simpson from Totally Spies and Ivy from Where On Earth Is Carmen Sandiego?). At her age, she is 14 years old.
- Amelia Hollister (Mother)
- Marshall Hollister (Father)
- Amanda Hollister (Younger Sister)
- Gary Oak (Love Interest)
- Roy Harrison (Total Crush)