Bowser's body is a location from Mario & Luigi: Bowser's Inside Story and its remake. After Bowser, under the influence of the Vacuum Shroom, inhales everyone at Princess Peach's meeting, Mario and Luigi must search for the missing princess within his body.
On the map of Bowser's body, large areas that typically contain many enemies are represented by green circles. Smaller areas that consist of a few screens are denoted with blue circles. Single-screen areas where Mario and Luigi play minigames are marked with red circles. Challenge Node, the only location with a unique color, is marked by a yellow circle.
When an enemy is inhaled by Bowser in the DS version, the battle background corresponds to the current location of Mario and Luigi on the map of Bowser's body. A generic background with an appearance similar to the final cutscene is used for areas where no battles would otherwise take place. Despite having proper battles take place here, being in the Flame Pipe or Memory Banks will use the generic background. Similarly, the Challenge Node does not use the background of the Gauntlet or Cholesteroad. In the 3DS version, the generic background is used for all battles, except for the final battle.
- Trash Pit - Bowser's colon. Mario, Luigi, and Starlow start their journey here after Bowser inhales them.
- Funny Bone - A sensitive area in Bowser's spine that, when attacked, causes Bowser to awaken from unconsciousness.
- Toad Square - An area where the Toads, who have also been inhaled by Bowser, amass all the junk they have found and set up shop.
- Challenge Node - An area in Bowser's spleen where Mario and Luigi can participate in the optional events, the Gauntlet, Cholesteroad, and test their jumping skills on the 99 Block.
- Arm Center - The locations of Bowser's arm muscles. From here, the Mario bros. can increase Bowser's strength by stimulating his arm muscles. (Plack Beach, Dimble Wood (x2), and Bowser Path)
- Pump Works - An area in Bowser's esophagus that fills with water when Bowser drinks from a fountain. Toadsworth is rescued here. (Plack Beach)
- Flame Pipe - A passageway in Bowser's chest responsible for his ability to breathe fire. A Scutlet temporarily blocks this passage, disabling his fire breath. (Plack Beach)
- Gut Check - Bowser's stomach. Here, the Mario bros. help Bowser digest a large carrot. The second Star Cure is obtained here. (Dimble Wood, Bowser's Safe)
- Nerve Cluster - An extremely sensitive area in Bowser's elbow nerves. When Durmite's presence invokes great pain, the Mario bros. track her down and defeat her. (Dimble Wood)
- Rump Command - In Bowser's tail. Whenever Bowser is crushed by a large object, the Mario bros. must come here to give Bowser an adrenaline boost to revive and cause him to temporarily grow to the size of a giant. (Dimble Wood, Blubble Lake, Traintracks, and Peach's Castle)
- Flab Zone - An area in Bowser's hip skin that swells whenever Bowser indulges himself with fatty food. Princess Peach and Alpha Kretin are found here. (Bowser's Castle)
- Leg Outpost - In Bowser's pelvis and the surrounding muscles. Stimulating the thigh muscles here helps Bowser push large objects. (Tunnel and Bowser's Castle)
- Nose Deck - Inside Bowser's nose. Whenever Bowser inhales pollen, the Mario bros. can help provoke a sneeze. (Blubble Lake (x3))
- Energy Hold - A maze in Bowser's liver loaded with special cells that are manipulated to appear, disappear, or even move via radiation from the Boo-ray Machine. Durmite (who is really Wisdurm) is followed here. (Tower of Yikk)
- Joint Tower - An area where Bowser's leg and hip form a joint. The body slam move is unlocked here. (Tower of Yikk)
- Memory Banks - Bowser's brain. All of Bowser's memories are stored here and overseen by a guardian. (Bowser's Castle)
- Lumbar Nook - Bowser's lower back. The spike ball is learned after the Mario bros. heal Bowser's back pain. (Peach's Castle)
- Chest Station - Contains tendons that, when stretched and released, spring Bowser's body in various directions. (Peach's Castle (x2))
- Airway - Bowser's trachea and lungs. The area freezes whenever Bowser inhales cold air. The Dark Star is fought here after it leeches some of Bowser's DNA. (Peach's Castle)
- Pipe Yard - In Bowser's ear, where there exist pipes for transportation in and out of Bowser's body to the Toad Town Caves, Toad Town, Blubble Lake, Bowser Castle, Peach's Castle and Dimble Wood.