The Ordinary Adventures of Tomas
- Photo-comic about Tomas, an invisible friend who doesn't realize he is invisible, and his many ordinary adventures.
- http://ordinarytomas.blogspot.com

Otaku Life
- An online comic strip about the secret life of college students and anime freaks. By Jeanette Brown.
- http://otakulife.comicgenesis.com/

Odd Jobs
- David DiAngelo's modern day strip Odd Jobs.
- http://oddjobs.comicgenesis.com/

Overcompensating by Jeff Rowland
- Comic strip rooted in reality. Archives, frequently asked questions, and forums.
- http://wigu.com/overcompensating/

Offenders At Large
- Evil Swamis, talking lizards, and sexy Secret Agents; welcome to a world where the best defense is a good offense.
- http://www.offendersatlarge.com/

Owlie Comics
- An archive featuring the grumpy owl fighting his battles with the universe.
- http://www.owliecomics.com/

On the Fly
- The chronical of Arney, a boy in a new town, in a new house with his newly divorced mom and a life that's just about to get interesting.
- http://www.impideas.com/onthefly/

Overdue Media
- Home of "Unshelved". Set in a library by Bill Banes and Gene Ambaum.
- http://www.overduemedia.com/

Order of the Stick
- Fantasy role playing oriented strip - includes cast of characters and some game design articles.
- http://www.giantitp.com/

Orneryboy by Michael Lalonde
- A comic strip about the adventures of a really moody boy and his perky girlfriend.
- http://www.orneryboy.com/

Ozy and Millie
- Two young foxes endure the trials and tribulations of childhood.
- http://www.ozyandmillie.org/

Over My Head
- A sampling of this single panel comic.
- http://www.clubi.ie/MarkF/yokes/

The Outer Burrows
- Surreal humor strip using found images, by Atrowbri and Zillno.
- http://www.outerburrows.com

OsigmaComics
- Features webcomic about a school in the UK featuring all the stereotypical characters and situations like world domination.
- http://www.freewebs.com/osigmacomics/

Spoil Sports
- Sports cartoons by Dominic Nunziato. A sports column in every cartoon.
- http://www.spoil-sports.com

Oh My Gods!
- A pagan based comic strip for the polytheistic masses. Features commentary and an archive.
- http://ohmygods.timerift.net/

Onion Head Monster
- Strange comics and animations about this misunderstood monster. By Paul Friedrich.
- http://www.onionheadmonster.com/

Over the Hedge
- Official website for the Over the Hedge comic strip.
- http://www.hedgeweb.com/

Off the Mark
- Mark Parisi's daily comic panel is on the web with a daily cartoon, archives according to subject, some stuff to buy and syndication information.
- http://offthemark.com/

Outta Toon
- The official web site of the humor comic strip Outta Toon.
- http://www.outtatoon.com

Old Motherboard's Tranquillity Haven
- Computer-related comics, cartoons and general humor by Roger Penwill.
- http://www.netlink.co.uk/users/penwill/haven.html

Over The Edge
- Daily Web panel cartoon by Dan Reynolds. With selected past cartoons archived, and originals, cards and t-shirts to buy.
- http://www.stus.com/ote.htm