As someone else mentioned, fetlife is not a bad avenue. Even if you're not a hardcore kinkster, as long as you're not completely appalled by it, there is a LOT of overlap in kink communities, and poly of various kinds.
I know lots of poly people in real life, but that's because I am involved with a BDSM club here, and people who are into one, are often into another.
Some folks try to use fetlife as a dating site, but I don't really recommend it. The real value in it for me (and others I know) is the events tab, which lists in various geographical cities and regions internationally, different meets going on for various interests. If you don't want to be bothered by random people trying to hook up there, you can usually say so on your profile, and you don't need to put up pics that show what you look like there, so you can fairly easily avoid random people messaging you.
However it's worth mentioning that the site is VERY "not safe for work"...even the ads are adult in nature.
Also, if you don't see any poly meetups in your area, you can always start one, and fetlife is a good place to promote it. Like reserving space at a restaurant for a social "get to know other people" sort of gathering, the kink scene calls them "munches." It's a thing. There might be more interested folks in your area than you think, and somebody has to be the first to set something up.
Best of luck!
