Answer:
Israel.
Step-by-step explanation:
If you are talking about who is occupying Palestine today, then it will be Israel. The two nations have been in conflict since 1948 and always hates each other. Palestine today is separated in 2 sides, one is Gaza strip and the other is the land on the East of Jerusalem.
Basically, Israel occupies Palestine and they want to take over Palestine because Israel believes that they deserve to own the land, and not the Palestinians.