Jet Cross-Sections and alphas in DIS at HERA

Measurements of inclusive-jet and dijet cross-sections in high-Q2 deep-inelastic scattering are presented together with a short overview of extractions of the strong coupling parameter alpha_S from jets. The data samples used were collected with the ZEUS detector at HERA-1 and HERA-2. The measured distributions are compared to QCD calculations in next-to-leading order which describe the data very well. The various determinations of alpha_S give a consistent picture, have competitive uncertainties and clearly demonstrate the running of the coupling predicted by QCD.