Evidence of dark matter from astrophysical measurements has opened a new era of searches for physics beyond the Standard Model. The ATLAS collaboration has developed a broad and systematic program to search for dark matter signals at the LHC. These searches are now entering their prime, with the LHC colliding high intensity protons beams at 13 TeV centre-of-mass energy and providing large amount of data in order to investigate the existence of such new physics. The results of some of these searches, their interpretation, and the design and possible evolution of the program will be presented.