Abstract: The Trailer Anti-Theft Locking Post is a device that is used to lock a trailer or other hitched device so that the trailer cannot be moved. The device may be anchored into concrete or secured unto the ground. A post reversible extends upward providing a means to lock a trailer or hitched device. When a user desires to move the trailer, the trailer is unlocked, and the post is reversibly retracted beneath the ground level, which puts the device out of sight and out of the way.