Bloomberg https://www.bloomberg.com/professional/product/market-data/

Or for those who don't have a ton of money to spend on it https://intrinio.com/data/realtime-stock-prices

This seems like a good choice, as it was mentioned by someone else, and I have consumed a few recently.

I'll look for a source...

The Investor's Exchange (IEX) offers the ability to resell their data stream for free, so that would be a good place to start. Getting real time stock quotes from other exchanges is going to be expensive.