Not a lot of places in Pittsburgh open early for breakfast before the sunrise, but Kelly O's Diner actually does open at 5am sharp!! My husband and I were looking for a place to stop by for breakfast after dropping our relatives off at the airport for their early morning flight out of PIT and we saw there was just not that many places to pick from that would be open early in the morning hours. We literally waited in our car 15 min before 5am in front of Kelly O's parking lot,not so sure if it would actually be open at 5am, but we're surprised and happy that it did...and on time, too!
The waitress was nice and friendly and not as crabby as we would have thought, given that it was 5am. Our meal was also large and they definitely did not skimp on the serving size.
I saw a few regulars came in as early as before 6am and the waitress recognized and greeted a few by names, too. Overall, a great place for breakfast with its own (and free!) parking lot. It also doesn't hurt that the diner was once featured in Guy Fieri's Food Network's Diners, Drive-ins and Dives, too!