Kick-off at Vicarage Road will be 3pm, as the Magpies look to progress to the next stage of the famous cup competition, which they have won six times – in 1910, 1924, 1932, 1951, 1952 and 1955.
Newcastle have met the Hornets six times in the FA Cup before – but four of those games were in one season.
In 1988/89, the teams drew 0-0 at St. James’ Park to set up a replay, which finished 2-2. That forced a second replay, which ended in another goalless draw, before Watford finally prevailed in the third replay, winning 1-0 at Vicarage Road.
However Newcastle did triumph over the Hornets at the third round stage in 1923/24. The Magpies won 1-0 in Hertfordshire – and went on to lift the cup that year.
And in 1931/32, United thrashed Watford 5-0 at the quarter-final stage, again going on to lift the cup at Wembley.
Ticket details for this season’s tie will be announced on nufc.co.uk in due course.