Ironclad

Iron Cross Army

Iron Fist (Bei Bang-Wen)

Iron Fist (Danny Rand)

Iron Fist (Orson Randall)

Iron Fist (Quan Yaozu)

Iron Fist (USM)

Iron Fist (Wu Ao-Shi)

Ironheart (Riri Williams)

Iron Lad

Iron Man

Iron Man (Iron Man 3 - The Official Game)

Iron Man (LEGO Marvel Super Heroes)

Iron Man (Marvel Heroes)

Iron Man (Marvel War of Heroes)

Iron Man (Ultimate)

Iron Man/Tony Stark (MAA)

Iron Monger

Iron Patriot

Iron Patriot (James Rhodes)

Isaiah Bradley

J. Jonah Jameson

Jackal

Jack Flag

Jack Murdock

Jack O' Lantern

Jackpot

Jack Power

James Buchanan Barnes

James Howlett

Jamie Braddock

Jane Foster

Janus, the Nega-Man

Jasper Sitwell

Jazinda

Jean Grey

Jean Grey

Jean Grey (Ultimate)

Jennifer Smith

Jeryn Hogarth

Jessica Drew

Jessica Jones

Jetstream

Jigsaw

Jimmy Woo

Joan the Mouse

Jocasta

John Farson

John Jameson

Johnny Blaze

Johnny Storm

John Porter

John Wraith

Joseph

Joshua Kane

Josiah X

Joystick

Jubilee

Jubilee (Age of Apocalypse)

Juggernaut

Jule Carpenter

Julian Keller

Junta

Justice

Justin Hammer

Ka-Zar

Kabuki

Kang

Karen O'Malley

Karen Page

Karma

Karnak

Karolina Dean

Kate Bishop

Kat Farrell

Katie Power

Ken Ellis

Khan

Kid Colt

Killer Shrike

Killmonger

Killraven

King Bedlam

King Cobra

Kingpin

Kinsey Walden

Kitty Pryde

Kitty Pryde (X-Men: Battle of the Atom)

Klaw

Komodo (Melati Kusuma)

Korath

Korg

Korvac

Krakoa

Kraven the Hunter

Kree

Krista Starr

Kronos

Kulan Gath

Kwannon