Evidence says: yes.

Can an atheist be put there? Sure. Will it happen? Maybe. Assuming that god exists, that comes at his own discretion.

If Heaven exists I think an Atheist who has been a good, kind person in their lifetime will be getting in because they did those good things with no expectation of a reward in the afterlife because they were not expecting an afterlife, so they were just a decent, kind person, that to me carries more weight than someone who did good things just so they would get a reward in the afterlife, or worse played the role of the good religious person but then enjoyed the torment of others or did nothing to help anyone but themselves in life.

Just look at Christianity, Matthew 25: 34-45 teaches us that it is our actions not faith that will lead us to salvation and the kingdom of heaven, this supports an Atheist making it if his actions in life are good and heaven exists!!

I do not have the link but if I remember it correctly, the Vatican council decided that yes. Anyone who has a kind spirit and walks on the good path, no matter what belief he follows, can enter Heaven.

Even Pope Francis said an atheist can go to Heaven. Atheists do good deeds, too.