Catalogs and data.-- et al. ; Wide-area X-ray and far-infrared surveys are a fundamental tool to investigate the link between AGN growth and star formation, especially in the low-redshift universe (z ≲ 1). The Herschel Terahertz Large Area survey (H-ATLAS) has covered 550 deg2 in five far-infrared and sub-mm bands, 16 deg2 of which have been presented in the Science Demonstration Phase (SDP) catalogue. Here we introduce the XMM-Newton observations in the H-ATLAS SDP area, covering 7.1 deg2 with flux limits of 2 × 10-15, 6 × 10-15, and 9 × 10-15 erg s-1 cm-2 in the 0.5−2, 0.5−8, and 2−8 keV bands, respectively. We present the source detection and the catalogue, which includes 1700, 1582, and 814 sources detected by EMLDetect in the 0.5−8, 0.5−2, and 2−8 keV bands, respectively; the number of unique sources is 1816. We extract spectra and derive fluxes from power-law fits for 398 sources with more than 40 counts in the 0.5−8 keV band. We compare the best-fit fluxes with those in the catalogue, which are obtained assuming a common photon index of Γ = 1.7; we find no bulk difference between the fluxes and a moderate dispersion of s = 0.33 dex. Using the fluxes from the spectral fits wherever possible, we derive the 2−10 keV Log N−Log S, which is consistent with a Euclidean distribution. Finally, we release the computer code for the tools developed for this project. ; P.R. acknowledges a grant from the Greek General Secretariat of Research and Technology in the framework of the programme Support of Postdoctoral Researchers. A.D.M. acknowledges financial support from the UK Science and Technology Facilities Council (ST/I001573/I). F.J.C. acknowledges financial support by the Spanish Ministry of Economy and Competitiveness through grant AYA2012-31447. ; Peer Reviewed