production with the ATLAS detector.

The cross-sections of prompt and non-prompt production of J/ψ+W^± are being measured by the ATLAS Collaboration using the 139 fb^-1 Run II 13 TeV pp collision data set. The prompt production of J/ψ associated with a W^±, where both particles are produced in a single parton-parton interaction, provides constraints on models of non-relativistic QCD, especially in the realm of heavy quarkonia production. The measurement is an all-leptonic final state with J/ψ→μ⁺μ^- and W^±→l^±ν, and it is performed differentially in J/ψ transverse momentum and rapidity. Finally, the non-prompt measurement allows for the study of top production and b-quark fragmentation.