Measurements of single top-quark production in proton-proton collisions are presented based on the 8 TeV and 13 TeV ATLAS datasets. For the production of single top-quarks and single anti-top-quarks in the t-channel, the total production cross sections, their ratio, as well as measurements of inclusive and differential cross-sections are presented. Measurements of the inclusive and differential production cross section of a single top quark in association with a W boson, the second largest single-top production mode, are also presented. Smaller single top quark measurements in the s-channel and in association with a Z boson are also presented. All measurements are compared to state-of-the-art theoretical calculations.