The nearest airport to Ubud is Ngurah Rai International Airport (Denpasar). Upon arrival, you can opt for the following modes of transportation to reach Ubud Palace:
If you're already in Bali, you can reach Ubud Palace via the following:
Once in Ubud town, Ubud Palace is centrally located and easily accessible on foot from most parts of the town. It is a focal point in Ubud, so you can ask any local for directions, and they will be able to guide you.