Yes. You can take a bus (or mini-bus) to Oświęcim (Polish name for Auschwitz). There's a train too but it goes to the town, not to the camp. I would buy tickets in advance for the bus just in case; these can be pretty small "mini-buses". And show up early enough to snag a seat if you can. Buy tickets at the bus station next to the train station - tell them you want to go to Oświęcim, to the camp. They'll know; few tourists would buy a ticket just to the town.
The one tricky thing I recall (this was 2012) about taking the buses was that I had been told they would pick up in the camp parking lot to return to Krakow, but the expected buses never came. (They have a schedule inside for buses which is what I was relying on.) The incoming bus dropped us off on the road outside the camp parking lot, maybe a 1/3 mile walk from the camp entrance, so after waiting around in the parking lot for a while at the end and no bus, I just walked back out there and caught the next bus going the other direction back to Krakow.
In retrospect, and with more time, I might have taken the train back from the town of Oświęcim, had there been one at a convenient time, to try to retrace the route concentration camp victims might have taken to the camp. But I'm sure it would have taken longer to get back to Krakow than the buses.