What's good for killing ivy without harming nearby fruit trees?
The neighbouring land (not someone's garden) has a couple of
seriously overgrown ivy plants and they're growing onto my
property and also growing all over the fruit trees next to them.
I'd like some sort off weedkiller to kill them that won't harm the
trees.

You could just locate the places where they connect to the earth and
cut them there. They need roots.