It turns out that the castle is the first main area of the game, with you exploring it as you being your attempt to find Ethan's daughter.
However, once you're out of it, you might want to get back in to find some of the secrets you missed.
We're here with the answer to whether you can or not.
Read More - Resident Evil Village Complete Walkthrough
Getting Back Into the Castle in Resident Evil Village
The short answer is no, you cannot get back into the castle after you reach a certain point in the story.
From here, there will be some spoilers to the early parts of Resident Evil Village's story, so don't read any further if you're not already out of the castle.
Once you find the four masks scattered around the hall of the castle, and escape, you'll be chased by Lady Dimitrescu and will have to fight her in a boss battle.
You'll find a dagger in a coffin, will stab her, and you'll fight her monster form for the right to escape.
From here, you'll be back in the town's main village, but with more freedom to explore this time.
As you progress through the rest of the game, you'll be sent to other parts of the region, but the gate to the castle that you opened right at the start will always remain open.
However, go through it and you'll find that the drawbridge is up, stopping you from getting back into the castle to clear up anything you missed.
Therefore, you'll have to wait for another playthrough to see everything, or make sure you do so the first time, before leaving.