How do I keep neighborhood cats off my outdoor furniture?

https://www.alleycat.org/resources/how-to-live-with-cats-in-your-neighborhood/

Talk to the neighbor first and see if they are will to keep cats from your furniture. Otherwise, keep some cayenne pepper spread around and even on furniture till then realize the furniture is not a place for them.

In most states there is an animal ordinance that says animals need to be on a leash or stay in a fenced yard. Find out what your state or county says. Then tak photos of the damage. Present a bill to the neighbor. unless you get a dog it is impossible to keep cats out.

Remove the cushions

There are some pet repellents but some of them STINK!!! Go to the pet store and check out their products and smell them before you purchase!

You can spray with a vinegar and water solution. Sprinkle dried red pepper flakes. Put peppermint oil around. Put mothballs in a plastic bowl, with holes in the bowl.

Peppermint teabags or mint, if you have it in your garden