Main cast •
Mary-Kate Olsen as Mary-Kate Burke – A 12-year-old tomboy who loves sports, horses, and modeling. She has two friends, Max and Brian. She also has a math tutor named Taylor. Mary-Kate has
Dyscalculia. Mary-Kate's favorite color is red. •
Ashley Olsen as Ashley Burke – A 12-year-old girly girl who loves fashion, dancing, make up, cheerleading, and modeling. Ashley's a Straight A student. She's better at math than Mary-Kate. Ashley also has a first crush when Mary Kate's math tutor Taylor Donovan came over. She's friends with Nicole and the popular Jennifer Dilber. In "Carrie Moves In" Ashley joins Mary-Kate's karate class. Ashley's favorite color is green. •
Christopher Sieber as Kevin Burke – The uptight father of Mary-Kate and Ashley. He is a strict, but loving parent who constantly worries about them. He is a widower; his wife Jan died three years prior to the series. With the encouragement of Carrie and Eddie, he reenters the dating scene. Kevin plays the saxophone. •
Sally Wheeler as Carrie Moore – The bubbly, free-spirited babysitter of the twins, and a student of Kevin. Her confidence and ambition often drive Kevin crazy, but he sees that she is a good mother figure for the twins. She is an older student, having dropped out to explore the world for several years. Carrie eventually moves into the Burkes’ basement after Kevin accidentally causes her to get evicted from her apartment. •
Orlando Brown as Max (episodes 1–13) – Mary-Kate and Ashley's friend and classmate. He seems to be very close with Brian. •
David Valcin as Edward "Eddie" Fairbanks (episodes 2–14) – Kevin's best friend since childhood, a flirty divorcee and professional plumber. He is known for constantly hitting on women and butting heads with Carrie. •
Jesse Lee as Taylor Donovan (episodes 2–8) – Mary-Kate's math tutor and Ashley's first crush. •
Martin Spanjers as Brian (episodes 1–13) – Mary-Kate and Ashley's friend and classmate. Although he is known to flirt with every girl at school, he has a crush on Ashley. •
Ernie Grunwald as Paul (episode 14–22; previously recurring) – Carrie's classmate. He is a computer whiz also has a Saturday job as a pizza delivery guy. He has a crush on Carrie but is too afraid to admit it.
Recurring cast • Anastasia Emmons as Jennifer Dilber – Ashley's friend. Jennifer is the most popular girl in 7th Grade. Ashley invites Jennifer to a sleepover that she has in the hopes of becoming popular and getting to sit with her at lunch. •
Samantha Smith as Nancy Carlson, Carrie's high school friend who dates Kevin. She is a
botanist. •
David Lascher as Matthew "Matt" Burke – Kevin's irresponsible younger brother. He briefly dated Carrie.
Notable guest stars •
Kimberly J. Brown as Nicole, Ashley's friend ("You've Got a Friend", "My Boyfriend's Back") •
Patrick Fabian as Alex Reardon, Carrie's ex-boyfriend ("My Boyfriend's Back") •
Blake Foster as Carter, a boy in Mary-Kate's karate class that she develops a crush on ("Carrie Moves In") •
Amanda Fuller as Courtney Collins, the school head cheerleader that propositions Ashley to join the squad ("Kevin Burke's Day Off") •
Emile Hirsch as Jeremy, a boy that Mary-Kate develops a crush on who is into swing dancing ("Let's Dance") •
Jean Speegle Howard as Mrs. Baker, an elderly neighbor of the Burkes who was also Mary-Kate and Ashley's babysitter prior to Carrie being hired ("Putting Two 'N' Two Together", "Peeping Twins") •
Rance Howard as Mr. Fillmore, a neighbor of the Burkes who becomes Mrs. Baker's boyfriend ("Putting Two 'N' Two Together", "Peeping Twins") •
Claire Stansfield as Tarrah James, a supermodel who asks Kevin on a date ("Model Behavior") •
David Sutcliffe as Rick, an arrogant student of Kevin ("First Crush") •
Wayne Tippit as Father Conrad ("A Very Carrie Christmas") •
Hallie Todd as Marci, Kevin's girlfriend ("Breaking Them Up Is Hard to Do") •
Paul Willson as Lenny, a pet store owner ("The Heartbreak Kid") ==Theme music and opening sequence==