Aldeguer is currently competing in Moto2 and won the final four races of last season, finishing third overall. He is widely expected to join the Pramac satellite team.
Ducati Corse general manager Luigi Dall'Igna said in a statement that Aldeguer was one of the strongest riders in the new generation of MotoGP.
"Over the last few years, we have followed his evolution; during the last season, he showed incredible speed. He is a very young guy with the potential and characteristics to do well, and we will give him all the technical support to help him grow."
The rider said he was realising a childhood dream.
"The time has arrived to take the big leap and compete with the world's finest riders, and what's more I'll be doing it with the best bike on the grid," he said.
