The 1999 Italian motorcycle Grand Prix was the fifth race of the 1999 Grand Prix motorcycle racing season.

It took place on 6 June 1999 at the Mugello Circuit.

Loris Capirossi was black-flagged for causing Marcellino Lucchi's crash at the start of the race;[6] in addition, as he did not return to the pits within one lap after having been shown the flag, he was banned from the following event.

[7] Below are the standings for the top five riders and constructors after round five has concluded.

[10]