Does he understand that not everyone likes or enjoys that level of physical touch? Does he understand that what might be fine with someone he knows well (if they agree) is not appropriate with someone he doesn't know well? Does he get the idea of personal space? Does he get boundaries and consent?
If the answer is 'no' or 'maybe?' to any of these questions, Monogamish1, then start there. And if he can't quite wrap his head around it, then he still needs to act as if he did 'get' it. There are lots of things I don't quite get myself but I accept as true anyway. (Like how much people love avocado?! Why?)
One simple way for him to reduce his creep factor - and he does come across as someone I'd avoid like the plague even if he is otherwise a decent sort - is to always ask if someone would like to be touched. (And then wait for a response and respect that response. And how important it is to not take any response personally. A 'yes' doesn't mean they think he is awesome and he can touch them any way he wants. A 'no' doesn't mean they think he is the dregs of the universe.) 'Would you like a hug?' 'Can I rub your back?' Yes, this can be awkward but there is no social cost to it and it might really help his 'standing' in your circle of friends and family.
The last thing I'd mention to him is the social cost to yourself and to him. If he is not noticing the impact of his actions, point them out. If someone is avoiding him, point out that's a consequence of his behavior. If he is making someone uncomfortable, point out their body language and explain it to him. And that it is his job to fix the behavior even if he can't get why it's a big deal.
Also, while his behavior might be tolerated by most as harmless and with no ill intent, he is probably being labeled as what my younger friends call 'That Guy'. This is the term they use for people (men or women) whose inappropriate behavior (in whatever way) eventually gets them pushed out of the social group. They are invited to less and less social gatherings, people are not so interested in drinks after work or having play dates with their kids together. And the thing about being 'That Guy' who has a partner is that the partner is cut out too. People have no problem with him or her, but their partner is a pain in the ass and, while they feel bad, the partner gets ostracized too. This might be happening to you. If it is, point that out. He needs to know.
There are people out there who use 'not knowing' or 'not understanding' as the excuse for continued bad behavior. I assume your partner is not one of them but I have met people who claim their 'ignorance' or 'inability' to follow social norms makes their behavior ok. 'That's how they are.' It's really a form of very sophisticated manipulation and can be the hallmark of a predator. Your partner does not want to get labeled as a predator using ignorance as his access point. This is how he could be perceived, even if this is not accurate.
Finally, while people who do not want to be touched in that manner or at all by your partner should speak up, that is actually not encouraged by mainstream society. To be polite, one is expected to put up with 'harmless' touching, especially if female. It's not surprising most women have said nothing or tried to convey to him by body language that it was not wanted - which sounds like he completely ignores or misses. (Have a talk with him about how touch is impacted by gender norms.)
As someone who does not enjoy hugging people I have just meet - and living in a place where that is common - it gets bloody exhausting constantly having to stop someone else hugging me. And it's awkward, stops all conversations and basically I risk looking like an asshole. I'm willing to do it (most of the time) because I find hugging or otherwise touching strangers beyond a handshake to be incredibly intrusive. But it's tiring. So while people should tell him, they generally aren't going to. Do your partner a solid and start trying to educate him on these issues. If he can learn, it will be incredibly positive for him (and you too, ultimately).
If your partner wants an outside opinion on how his behavior may be impacting others, and you and him, I'm willing to talk with him via PM here.
