We introduce a diagrammatic monoidal category Heis k (z, t) which we call the quantum Heisenberg category; here, k ∈ Z is "central charge" and z and t are invertible parameters. Special cases were known before: for central charge k = −1 and parameters z = q − q −1 and t = −z −1 our quantum Heisenberg category may be obtained from the deformed version of Khovanov's Heisenberg category introduced by Licata and the second author by inverting its polynomial generator, while Heis 0 (z, t) is the affinization of the HOMFLY-PT skein category. We also prove a basis theorem for the morphism spaces in Heis k (z, t).