The first version of the Swift UVOT serendipitous source catalogue (UVOTSSC) provides positions and magnitudes, as well as errors and upper limits of confirmed sources for observations taken from start of operations in 2005 until October 1st of 2010. The first version of the Swift UVOT Serendipitous Source Catalogue (UVOTSSC) has been produced by processing the image data obtained from the Swift Ultraviolet and Optical Telescope (UVOT) from the beginning of the mission (2005) until 1st of October of 2010. The data processing was performed at the Mullard Space Science Laboratory (MSSL, University College London, U.K.) using Swift FTOOLS from NASA's High Energy Astrophysics Software (HEASoft-6.11), with some customising of the UVOT packages in order to get more complete source detection and properly apply quality flags to those sources that were detected within the UVOT image artefacts. The total number of observations with 17'x17' images used for version 1 of the catalogue is 23,059, giving 6,200,016 sources in total, of which 2,027,265 have multiple entries in the source table because they have been detected in more than one observation. Some sources were only observed in one filter. The total number of entries in the source table is 13,860,568. The S/N ratio for all sources exceeds 5 for at least one UVOT filter, the rest of the filters having a S/N greater than 3.
