Gordon O'Sullivan "Sully" is the team leader of the Danger Rangers. He is a spokes-sea lion and is safety driven, smart and funny. He often tells jokes and is a bit of a showoff. He is the action hero. Sully is somewhat funny and loves to tell jokes, especially puns.
Kitty is often the one to have the last laugh, when he shows off or tells jokes or tries to be a smart-alec, and he has a crush on her. His catchphrase is "Let's roll, Danger Rangers!"
Sully is one of the fewer Danger Rangers to ever mention their childhood, but unlike the other two Rangers, Kitty and Burble, there is no flashback scene of him as a kid.
- Mission 547: Safety Rules! (Pilot) (first appearance)
- Fallbot Forget-Me-Not
- Fire in the Sky
- Microbe Mania
- Take a Hike
- Traffic Trouble
- Come Home Captain Safety
- And They All Fall Down
- Unidentified Farmyard Object
- The Traveling Brayskis
- Kitty in Wonderland
- Sully is voiced by Jerry Houser. Houser also provides the voices for Shiner from The Biskitts, Slim from Annabelle's Wish and Nick from Nick and Noel.
- His favorite food is fish sticks.
- His favorite color is blue.
- Technically, seals and sea lions do not really have feet. Instead, they have flippers. However, Sully, mostly being on land like the others, walks with his flippers like feet.
- He is the Mad Hatter in “Kitty in Wonderland,” Prince Derek in “Kitty the Swan Princess,” Prince Philip in “Sleeping Kitty,” and Kristoff in “The Show Must Go On: A Christmas Play Adventure.”
- Sully is selfless and thoughtful.
- He and the other Danger Rangers often work as a team.