Alliances are a feature in Call of Duty: Heroes. Similar to clans, alliances are a group of allied players. Alliances are limited to twenty-five players. They are also able to fight together in Alliance Wars.

Players are able to create or join an alliance once they've repaired the Communications Center for 50,000Gold Icon CoDH. Players are able to request support from alliance members, who can send troops over to the player's base. These troops will help to defend the player's base if attacked, or can be used instead offensively in PvP battles. Heroes stay with the player only six hours before returning to the original player. The amount of troops a player can have increases as their Communications Center is leveled up.

Alliances are able to have private chats in-game. In addition, the shop offers various flags for purchase, which can be used as a symbol of the alliance.