We examine the residual (measured minus internal) magnetic field vectors observed in Saturn’s magnetosphere during the Pioneer-11 fly-by in 1979, and compare them with those observed during the Voyager-1 and -2 fly-bys in 1980 and 1981. We show for the first time that a ring current system was present within the magnetosphere during the Pioneer-11 encounter, which was qualitatively similar to those present during the Voyager fly-bys. The analysis also shows, however, that the ring current was located closer to the planet during the Pioneer-11 encounter than during the comparable Voyager-1 fly-by, reflecting the more com-pressed nature of the magnetosphere at the time. The residual field vectors have been fit using an adaptation of the current system proposed for Jupiter by Connerney et al. (1981a). A model that provides a reasonably good fit to the Pioneer-11 Saturn data extends radially between 6.5 and 12.5 RS (compared with a noon-sector magnetopause distance of 17 RS), has a north-south extent of 4 RS, and carries a total current of 9.6 MA. A corresponding model that provides a qualitatively similar fit to the Voyager data, determined previously by Connerney et al. (1983), extends radially between 8 and 15.5 RS (compared with a noon-sector magnetopause distance for Voyager-1 of 23–24 RS), has a north-south extent of 6 RS, and carries a total current of 11.5 MA. ; We would like to thank Stephane Espinosa for ´ the provision of Pioneer-11 magnetic field data, Joe Mafi of the Planetary Data System, UCLA for supplying the Voyager-1 and -2 magnetic field data employed. We would also like to thank Douglas Robinson and Karen Veal, who piloted elements of the work reported here during undergraduate research projects in the Department of Physics & Astronomy at the University of Leicester. EJB was supported during the course of this study by PPARC Grant PPA/G/O/1999/00181 and SWHC by PPARC Senior Fellowship PPA/N/S/2000/00197. ; Peer-reviewed ; Publisher Version