Welcome!
There are undoubtedly loads of companies out there that make poker chips (think ABS/metal slugged "dice chips"), but most of the discussion here revolves around us upgrading out chips away from those and seeking the best chips we can get a hold of without being a casino. So while there are many sources of poker chips, there are only a handful of companies that produce high-quality poker chips, such as those with a good feel, good materials (compression clay, ceramic, or injection molded plastic) and high manufacturing tolerances (good uniformity, no burrs, the right shape to stack and shuffle well and avoid "spinners", etc). And even out of these few options, there are only a couple that produce "casino quality" chips. But these chips are only as good as they are because of enormous investment by the businesses in equipment, R&D, etc.
The point is, if you're looking for good quality custom ceramics, you're in the right place for advice. Like
@Kid_Eastwood said, there's
@SUN-FLY Poker Chips ,
@ABC Gifts and Awards , and then the Chinese cards-mold vendors. Another great option if you don't like the look of home-market/off-the-shelf designs would be to buy a set of ChipCo ex-casino chips from the classifieds, these have such an amazing feel and you can't get them new anymore.
On the other hand, if you're here to take on the project of trying to develop your own chips, that sounds amazing. Alot of us here probably have that same dream, so again, you're in the right place.
@Grandmasturkey has a thread about his journey trying to make compression-clay chips that you might want to check out.
https://www.pokerchipforum.com/threads/so-it-begins-aka-poker-chip-making-quest.71526/