Zip folder containing synchrotron X-ray diffraction patterns (.xye files), scanning electron microscopy and scanning transmission electron microscopy images (.png files), and atom probe tomography measurements (.csv files) associated with a study of the ageing response of Cu-15Ni-8Sn (wt%). Diffraction patterns were collected from the ID22 beamline at the European Synchrotron Radiation Facility at room temperature and during thermal exposures as described in the file names. Data are partitioned into bins of 0.002 degrees. Scanning electron microscopy images were collected in backscattered electron mode, along with corresponding energy dispersive X-ray elemental intensity maps with an acceleration voltage of 20 kV. Scanning transmission electron microscopy images and corresponding energy dispersive X-ray elemental intensity maps were acquired with an acceleration voltage of 200 kV. Atom probe tomography data are presented as radial concentration profiles from reference Ni atoms.