Like all previous Super Smash Bros. games, Super Smash Bros. Ultimate has a varied character roster with characters from all parts of Nintendo's history. These characters include every single character ever playable in a Super Smash Bros. title and many new ones with more DLC to be added over the game's life.
| Icon | Character | Series |
 | Mario | Mario |
 | Donkey Kong | Donkey Kong |
 | Link | The Legend of Zelda |
 | Samus | Metroid |
 | Dark Samus | Metroid |
 | Yoshi | Yoshi |
 | Kirby | Kirby |
 | Fox | Star Fox |
 | Pikachu | Pokémon |
 | Luigi | Mario |
 | Ness | Earthbound |
 | Captain Falcon | F-Zero |
 | Jigglypuff | Pokémon |
 | Peach | Mario |
 | Daisy | Mario |
 | Bowser | Mario |
 | Ice Climbers | Ice Climbers |
 | Sheik | The Legend of Zelda |
 | Zelda | The Legend of Zelda |
 | Dr. Mario | Mario |
 | Pichu | Pokémon |
 | Falco | Star Fox |
 | Marth | Fire Emblem |
 | Lucina | Fire Emblem |
 | Young Link | The Legend of Zelda |
 | Ganondorf | The Legend of Zelda |
 | Mewtwo | Pokémon |
 | Roy | Fire Emblem |
 | Chrom | Fire Emblem |
 | Mr. Game and Watch | Game & Watch |
 | Meta Knight | Kirby |
 | Pit | Kid Icarus |
 | Dark Pit | Kid Icarus |
 | Zero Suit Samus | Metroid |
 | Wario | Wario |
 | Snake | Metal Gear Solid |
 | Ike | Fire Emblem |
 | Pokemon Trainer | Pokémon |
 | Diddy Kong | Donkey Kong |
 | Lucas | Earthbound |
 | Sonic | Sonic the Hedgehog |
 | King Dedede | Kirby |
 | Olimar | Pikmin |
 | Lucario | Pokémon |
 | R.O.B. | R.O.B. |
 | Toon Link | The Legend of Zelda |
 | Wolf | Star Fox |
 | Villager | Animal Crossing |
 | Mega Man | Mega Man |
 | Wii Fit Trainer | Wii Fit |
 | Rosalina and Luma | Mario |
 | Little Mac | Punch-Out! |
 | Greninja | Pokémon |
 | Mii Fighters | Nintendo |
 | Palutena | Kid Icarus |
 | Pac-Man | Pac-Man |
 | Robin | Fire Emblem |
 | Shulk | Xenoblade |
 | Bowser Jr. | Mario |
 | Duck Hunt | Duck Hunt |
 | Ryu | Street Fighter |
 | Ken | Street Fighter |
 | Cloud | Final Fantasy |
 | Corrin | Fire Emblem |
 | Bayonetta | Bayonetta |
 | Inkling | Splatoon |
 | Ridley | Metroid |
 | Simon | Castlevania |
 | Richter | Castlevania |
 | King K. Rool | Donkey Kong |
 | Isabelle | Animal Crossing |
 | Incineroar | Pokémon |
 | Piranha Plant | Mario |
 | Joker | Persona |
 | Hero | Dragon Quest |
 | Banjo and Kazooie | Banjo-Kazooie |
 | Terry | Fatal Fury |
 | Byleth | Fire Emblem |
 | Min Min | ARMS |
 | Steve and Alex | Minecraft |
 | Sephiroth | Final Fantasy |
 | Pyra Mythra | Xenoblade Chronicles |
 | Kazuya | Tekken |
 | Sora | Kingdom Hearts |