Activision O₂

Activision o2 was a sub-brand of Publisher Activision, created in 2001. It would serve as a umbrella brand for their line of action-sports games. It came off the up rise of popularity the Tony Hawk Pro Skater games received in early 2000, and was designed to appeal to both gamers and action-sport enthusiasts. The name Activision o2 was reported to be conceived around the idea of "big air", a highlight of all o2 products. The first title to launch with the brand name was Mat Hoffman's Pro BMX.

The games would center around a particular action sport, and mainly focus on one of its most relevant professionals at the time. Thus, the games that were published under the brand typically followed the same naming structure. On the foot of Tony Hawk's Pro Skater came Mat Hoffman's Pro BMX, Kelly Slater's Pro Surfer and Shaun Palmer's Pro Snowboarding. The only game that did not follow suit would be Wakeboarding Unleashed featuring Shaun Murray (It was however, originally titled Shaun Murray's Pro Wakeboarding). Motocross rider Travis Pastrana was also reported to get an o2 Pro game (Travis Pastrana's Pro MotoX). An early demo was featured in Tony Hawk's Underground. However, the game was eventually released as MTX Mototrax in 2004, under regular Activision publishing. 

The sub-brand appeared to lose relevance in 2003. Wakeboarding Unleashed would be their last published game.

Present in most of the o2 branded titles were the inclusion of other games' cover athletes as secret characters.