Tsunade is the granddaughter of the first Hokage, Hashirama Senju. She served as the fifth Hokage of the Hidden Leaf but where is she now in Boruto? Is she dead?
As far as we know, Tsunade is still alive. After the Fourth Shinobi World War, Tsunade retires as the 5th Hokage, and she may have continued her tradition with leaving Konoha after the Second Shinobi World War when she retired as a Shinobi.
While details to Tsunade's whereabouts in the Boruto series have not been fully released, we do know she is still alive during the 5 Kage Summit in Naruto Chapter 700. This 5 Kage Summit occurred 15 years after the Fourth Shinobi World War, which was called by the 7th Hokage
Fifteen years after the Fourth Shinobi World War, another Kage Summit is convened in Konohagakure by the Seventh Hokage.
During this summit, Tsunade reunited with the other retired Kages
Tsunade attends Naruto's marriage to Hinata Hyūga. Yamato runs around prior to the ceremony making final preparations, which Tsunade occasionally offers advice on.
Twelve years later, while a Five Kage Summit was being held in Konoha, Tsunade and the other retired Kage visit the Third Tsuchikage to, as Tsunade puts it, get drunk and complain about things.
Right now it's too soon to definitively say; she was still alive at the end of Naruto Shippuden so we can assume that she will become a more significant character later in the series.
Not all characters from Shippuden have been brought into Boruto yet in the anime or manga. Give it time and we will see.