Bailey Carson Belvedere III is Muffy's butler and chauffeur. He is very good at art and built many sculptures for Muffy's art show. He does everything he's told, even doing a wheelie with the limo. He has worked for the Crosswire family for ten years and has a room in their mansion.
Bailey often gives advice to Muffy when she needs it. He admitted that he actually enjoys doing his job, despite it involving a lot of hard work for him. He also admits that it is never dull for him. In his years at elementary school he was picked on, one of the bullies being a kid (now adult) named Chester. He also calls Muffy, "Miss Muffy."
Bailey is an anthropomorphic beige dog. He wears brown shoes, gray trousers, a white shirt with a red tie under a dark gray suit jacket.
- For his first appearance he was called James, but his name changed to Bailey in the episode "Poor Muffy."
- However, in "The Butler Did...What?", Mr. Ratburn makes a point that 'Bailey' could be his last name.
- This refers to the show's director, Greg Bailey.
- His room has a picture from high school, where it is revealed that he went to high school with Mr. Ratburn. They were in the high school band together in 1979-1980.
- He is miscolored in certain episodes, notably "Muffy's New Best Friend" and "The Play's the Thing."
- He plays badminton. In "The Tardy Tumbler," Muffy says that she has a badminton match with him. In "The Case of the Girl with the Long Face," Muffy noted how he sprained his elbow playing.
- Arthur Goes to Camp 10701
- Arthur's Lost Dog (Cameo) 11202
- Arthur and the True Francine 11402
- Meek for a Week (Cameo) 11701
- Poor Muffy 12601
- D.W., the Picky Eater 20301 (Mentioned)
- Arthur Makes a Movie (Cameo) 20401
- Arthur's TV-Free Week 20701 (Fantasy)
- Water and the Brain 21301
- Fern's Slumber Party (Cameo) 21502
- Arthur Goes Crosswire (Cameo) 30301
- Sue Ellen and the Brainasaurous (Cameo) 30302
- Background Blues (Cameo) 30401
- Revenge of the Chip (Cameo) 30502
- Arthur's Almost Live Not Real Music Festival 31102
- Muffy's New Best Friend 40201
- Sue Ellen Gets Her Goose Cooked (Cameo) 60101
- Best of the Nest 60102
- Rhyme for Your Life 60801 (Mentioned)
- Pick a Car, Any Car (Cameo) 70601
- Jenna's Bedtime Blues 70602
- Muffy's Art Attack 80801
- Buster's Green Thumb (Cameo) 90401
- Lights, Camera... Opera! 90502
- The Curse of the Grebes (Cameo) 100601
- World Girls 100902
- Prunella Packs It In 110302
- Phony Fern (Cameo) 110401
- The Making of Arthur (Cameo) 110601
- Spoiled Rotten! 110902
- Room to Ride 120201
- Bats in the Belfry (Cameo) 120302
- For the Birds (Cameo) 120401
- The Cherry Tree 120601
- Matchmaker, Match Breaker 120602
- The Great MacGrady (Cameo) 130100
- The Silent Treatment (Cameo) 130201
- No Acting, Please (Cameo) 130501
- The Play's the Thing 140302
- All the Rage 140802
- Buster's Secret Admirer 150301
- Cents-less 150401
- Buster's Carpool Catastrophe 150602
- Muffy's Classy Classics Club 150801
- Through the Looking Glasses 150902
- The Butler Did... What? 151001
- Muffy Takes the Wheel 160202
- The Last Tough Customer (Cameo) 160601
- Sue Ellen Vegges Out 160902
- Ladonna Compson: Party Animal (Cameo) 170202
- Molina's Mulligan (Cameo) 170301
- Just the Ticket 170402
- Go Fly a Kite 170702
- Caught in the Crosswires 170901
- D.W. & Bud's Higher Purpose 180102 (Mentioned)
- The Friend Who Wasn't There 180201
- The Case of the Girl with the Long Face (Cameo) 180301
- Best Wishes (Cameo) 180401
- The Tardy Tumbler 180402 (Mentioned)
- Fountain Abbey (Cameo) 180501
- Messy Dress Mess 180702 (Mentioned)
- Shelter from the Storm 181000
- Sue Ellen Adds It Up (Cameo) 190201
- Wish You Were Here (Cameo) 190202
- Arthur's Toy Trouble (Cameo) 190301
- Spar for the Course (Cameo) 190302
- Francine's Cleats of Strength 190801
- Lend Me Your Ear (Cameo) 200501
- The Butler Did It 200502
- Sue Ellen & the Last Page 210302 (Mentioned)
- Muffy Misses Out (Cameo) 210401
- Take a Hike, Molly 210502
- "Arthur and the Haunted Treehouse"
- Arthur Its Only Rock n Roll (Cameo)