|Full Name||Mackenzie Gardner|
|Nickname(s)||Kenzie (by everyone)|
|Date of Birth||1999-2000|
|Relationships||Hayden Warren (ex-boyfriend)|
|School(s)||Lake Munro High School|
|First Episode||Everywhere You Look (2706)|
|Last Episode||Comes and Goes (2) (3015)|
|Portrayed By||Sabrina Carpenter|
Mackenzie Gardner is a graduate in the class of 2018 at Lake Munro High School.
Starts Lake Munro in season 27, she hangs out with a bad crowd. She befriends Kendall after Kendall comes to her for drugs to cope with her mother. In season 28, she and Kendall hang out more, which angers Kendall's mother. In season 29, after a night of partying and drug use, she wakes up on the other side of town. Although not being seriously hurt, she uses this as a wake up call and tries to get herself back together. Later, after Kendall runs away, she and Kendall's brother Hayden try and look for her. While they are searching they talk and begin to have feelings for each other. They begin dating. In season 30, Hayden tries to get her off drugs. At first, she refuses any help from him, but later agrees to get enrolled in a program. Later, she and Hayden break up after they both agree they don't feel the same way anymore, however they remain friends and Hayden continues helping her through her program. Later, after doing well in the program, she decides to enlist in the military. She is nervous she will be denied because of her drug history, but she is accepted which makes her happy. Later, she is seen graduating with her class. She is last seen saying goodbye to Hayden before leaving for the military.
- She has appeared in 32 episodes.