I’m doing this from memory since I can’t find a definitive list, but I think I’m getting it right.

The very first subreddit was /r/nsfw. That was to get all the NSFW content off the main page. Technically at that point /r/reddit.com became a subreddit too, but it wasn’t addressed that way until later.

The next one was /r/programming, to get the programming content off the front page. Then came /r/politics.

All of these were created manually by the admins as a way of segregating content that was dominating the front page.

A few days after I started at reddit, I created /r/netsec, because now that I was on the inside I could do that manually. I wanted a place to discuss network security related items.

A few months later Conde Nast wanted a couple of subreddits that would be easier to sell ads on, so we created eight subreddits. I don’t remember all of them, but two of them were /r/entertainment and /r/gadgets. I think there was a fashion one too.

There may have been a few more subreddits created by other employees as well but I’m not sure. Basically they would all have been things of personal interest to us.

Then we created the ability for users to create subreddits. The very first user created subreddit was /r/cogsci (created by me to test the feature). I also created /r/berkeley shortly thereafter (which I think was the first University subreddit), but there were many others created before that. I think /r/pics was created on the first day.