Can landlord enter my room whenever they feel like UK?

I answered your other question, but now I see that your housemate is actually the owner.  There's a big difference between being a lodger and being a tenant in UK law.  Most tenant rights don't apply to lodgers.  From your other questions I think that you should start quietly looking for another place.  Don't tell your landlord though or I get the feeling that she might kick off and you don't want to end up suddenly homeless.  I think there's something wrong with her and staying with her will be stressful for you, as well as for anybody else.  

PS security cameras are cheap.  Get a cheapo one and point it at the door of your room, then ask her what that's all about (once you've someplace else to go).

As a lodger you signed a contract, to find the answer to your question you need to read it and see if you signed an ‘excluded licence’ which gives your landlord the right to enter ANYWHERE in their home including the room you rent or an ‘excluded tenancy’ which enables you exclusive use of your own room and your landlord isn’t allowed to enter without first giving you notice of doing so...... landlords do not 'need permission' from any tenant/lodger to enter their own property, however they do in most cases need to give notice they intend to

You are a lodger and that doesn't quite give you the same rights as a tenant, or where the landlord doesn't live on the premises.

As to the landlord being able to enter your room, well that depends on the agreement you have with your landlord.

The following is taken from Citizens Advice website, as they probably explain it better than I can:

- There are 2 types of agreement you might have with your landlord - you’ll either have an ‘excluded licence’ or an ‘excluded tenancy’.

You’ll probably have an excluded licence if your agreement doesn’t give you exclusive access to any area in the property and your landlord can go wherever they like.

You’ll have an excluded tenancy if you have exclusive use of your own room that your landlord isn’t allowed to enter. You’ll still share other living space with them -----

It comes from a much longer article, which it might be worth your while reading. Check out their website

Did you sign a contract? Did you read and understand the contract?  It says there what you agreed to.

. Suspecting is not the same as KNOWING.  Then ask yourself WHY would they need to enter your room?  Personally I think you be paranoid. UNLESS YOUR ROOM HAS A STOVE AND SINK.   Then they could just be coming in to be sure all the stuff is shut off. so no fire happens...or flooding.

.  You are a lodger. You pay rent, right?  Then you are buying privacy.  They have no right to come in. They need your permission for a specific reason that makes sense to you.  Find out and let us know.

Yes and no, I think it would be useful to let your landlord know it would be nice to have a little privacy.