Where is the seriel number of a waltham pocketwatch?

The serial number of a Waltham pocket watch is typically located on the movement, which can be accessed by removing the case back. It is usually engraved on the plate of the movement, often near the balance wheel or the mainspring. In some cases, the serial number may also be found on the inside of the case back. If you have difficulty locating it, consulting the watch's manual or a professional watchmaker may help.