No it weill not, says so in the item description. Only Milestone that will work on AT&T is the Telus version so I recommend you search for Telus Motorola Milestone. That is how I got mine. Then if it is not unlocked you will have to use a service to unlock it. I used MobileInCanada. More spendy than others but recieved my Subsidy Unlock code in about three hours vs a couple days like others.