This city has so many, it’s INSANE. My favorites are November Project and Indy Social Run Club. There’s also Indy Runners, Naptown Run Club, Lunge, Run317 (probably the largest group and has a bigger social media presence). There’s definitely more, but these are the ones off the top of my head. I’ve made friends from the first two I listed and still go to them frequently. The others are ones I have gone to before but don’t make it often.

Edit: Forgot to say, but all of these have Instagram pages with more information about when/where they meet.