The present invention relates to adjustable mounts, and in particular to an adjustable mount that can be selectively locked in position by way of a position locking mechanism. The mount assembly generally comprises a base coupleable to a structure, a tilt plate coupleable to the device and pivotally connected to the base, and a position locking mechanism. The position locking mechanism generally comprises a linkage member extending between the base and the tilt plate, and a lock that is selectively adjustable between an unlocked state in which the linkage member is free to move relative the base thereby allowing the tilt plate to pivot about the base, and a locked state in which the linkage member is retained in position by the lock relative the base thereby preventing the tilt plate from pivoting about the base.