This search focuses on high-mass resonances using the latest data collected by the ATLAS detector at the LHC, which has an unprecedented centre-of-mass energy of 13 TeV. The search is conducted for resonant new phenomena in dimuon final states. The dimuon invariant mass spectrum is the discriminating variable used in this search. No significant deviations from the Standard Model expectation are observed. Lower limits are set on the signal parameters of interest at 95% confidence level.