The new device features a 6.2in screen which folds together when closed, with another, smaller screen to display notifications on its outer shell.
The device will be sold for $1,500, starting in the US on 26 December, with other markets coming later.
Analysts told the BBC they did not expect the device to have much impact on the global smartphone sales.
“The question everyone will be asking is whether this foldable device will change Motorola fortunes, because their market share is extremely small,” said Francisco Jeronimo, an analyst with IDC. "Honestly, I don’t think it will."
But the new Razr is, at the very least, being seen as an innovative statement piece from Motorola, which is now a unit of Chinese giant Lenovo, having being acquired - from previous owner Google - in 2014.
“In the current era of similar looking black rectangular phones with touch screens, the new Motorola Razr has the potential to bring some excitement back into the market,” said Ben Wood, from CCS Insight.
"I have little doubt that Lenovo will struggle to keep up with demand as soon as it is available to buy.”
Reports prior to the device’s launch suggested only 200,000 units would be available - but the company would not confirm this.
It will come to the UK in early 2020, and be exclusive to EE's network.