Series starting with X
- X 2013
- X-23 (2010)
- X-23 (2018)
- X-23: The Complete Collection
- Xanth
- Xaviera
- Xaviera Hollander
- X-Calibre
- X-Corp
- X-Corp by Tini Howard
- Xeelee Sequence
- Xenaro
- Xenogenesis
- Xenolinguist Guild
- Xenowealth
- X-Factor (2005)
- X-Files Anthology
- X-Force
- X-Force (2008)
- X-Force by Fabian Nicieza
- X-Men (2004) (Collected Editions)
- X-Men (2010)
- X-Men (2019 Single Issues)
- X-Men: Age of Apocalypse
- X-Men: Age of Krakoa (Anthology Trades)
- X-Men Epic Collection
- X-Men: First Class - Digest Size Collection
- X-Men: Gambit Classic
- X-Men (Krakoan Age)
- X-Men Legacy (2008) (Collected Editions)
- X-Men: Manifest Destiny
- X-Men Milestones
- X-Men: The Krakoan Age
- X-Men Visionaries
- XML Bible
- X-O Manowar (2017)
- Xombies
- XOXO
- X-Ray Robot
- X-Statix (Collected Editions)
- Xtreme
- Xtreme Jobs
- XX век - The Best