Samuel "Sam" Thomas is the fifteen-year-old son of Elizabeth Thomas-Brewer and Patrick Thomas, younger brother of Charlie Thomas, older brother of Kristy and David Michael Thomas, stepson of Watson Brewer, stepbrother of Karen and Andrew Brewer and adoptive brother of Emily Michelle Brewer.
Sam dark curly hair, sparkly blue eyes, and a few freckles.
Sam is currently a sophomore at Stoneybrook High School with Charlie Thomas. He plays intramural basketball with Charlie as revealed in Kristy and Mr. Mom. He is a member of the math club and plays the clarinet in the marching band.
He used to share a room with Charlie at the beginning of the series before moving. Sam delivers groceries for A&P part time during the school year. During the summer, he was a camp counselor. In Karen's Paper Route he and Charlie pick up Kristy and Karen's paper route after he gets fired when the store over hired.
He teases and jokes around a lot with David Michael. Sam is a champion practical joker and also a troublemaker, who gets detention. He helps Kristy play a practical joke on Betsy Sobak in Claudia and the Bad Joke.
He went out with Stacey McGill a few times, but considers her a friend.
In Kristy's Big News, he was invited to his father's wedding and he wanted to go. Kristy makes a remark that he really wanted to go on a free trip to California and was neutral talking about the wedding. He had tried hard to get to know his dad and talk to him.
- Likes anchovies on his pizza (M#9)
- Girls are always on his mind
- Kids (sometimes)
- Singing in the shower
- Goof calls (SS#8).
- Ricky and Randy Jones (childhood)
- John Hastings (LS #17)
- Mouth (LS #17)
- Hanson Family
- Brian Durang (LS#106 and SS#9)
- Mark (LS#106)
- Robert (LS#86)
- Stacey McGill (has a crush on her; went out a few times, but thinks of her as a friend by Stacey and the Boyfriend Trap.)
- Tamara (sat with her at lunch and took her to the movies in #2)
- Amanda Martin (gave some roses)
- Monique (hated her, but also liked her)
- In Karen's Tuba Sam gave Hannie Papadakis and Karen Brewer lessons on how to play their instruments. He taught Ms. Colman's class to play Here Comes the Bride for a concert.
- He set the spaghetti sucking record by doing it twenty-seven times, as mentioned in The All-New Mallory Pike.
- He is in math club.
- He knows origami in Claudia and the First Thanksgiving.
- Kristy notes that he's a lot like Patrick Thomas in Kristy's Big Day.
- Sam narrates a chapter in Baby-sitters at Shadow Lake and a chapter in Starring the Baby-sitters Club!.
- He is called Sam Brewer in a chapter of Dawn on the Coast.
- Sam pulled a prank on Karen Brewer and Jessi Ramsey making them think the third floor was haunted in Dawn on the Coast.
- He has a really loud voice in Kristy's Mystery Admirer.
- In Kristy's Great Idea, Kristy mentions that he once baby-sat for Karen and Andrew before.
- Karen remarks that he gets grumpy in the morning in Karen's Little Witch.
- In Karen's New Teacher, Sam tells Karen that he and a classmate named Jeremy play pranks on substitute teachers, sometimes even their regular teachers.
- He gets a job washing dishes at the Five Happiness restaurant in Karen's Fishing Trip.
- Sam became class president sometime before Karen's Chicken Pox.
- He knows how to ride a unicycle in Baby-sitters' Haunted House.
- Sam knows how to drive a boat as of Baby-sitters at Shadow Lake, he also notes that he can't wait to shave and drive.
- He's right handed in Baby-sitters at Shadow Lake.
Sam is played by actor Dylan Kingwell. In this adaptation, he has dark brown hair and hazel eyes, and seems to be a mix of both his older brother, Charlie, and his younger sister, Kristy.