The Sveconorwegian belt is a broad terrain in the south western sector of the Fennoscandian Shield subjected to thermal activation, widespread intrusion and limited tectonic activity between ca. 1100 and 950 Ma, and magnetised during slow uplift and cooling following these mobile events. This study comprises a palaeomagnetic investigation of four areas spanning the zone: the anorthosite, farsundite and related intrusive complexes of southwest Norway, the gabbro-norite intrusions of the Bamble sector bordering the Oslo Graben, the gabbro-anorthosite complex at Brattön and Älgön in west Sweden, and dolerite intrusions near the eastern tectonic front to the zone in Sweden. Site mean directions and demagnetisation trends in the Rogaland intrusive complex define an apparent polar wander (a.p.w.) swathe of just over 30° of arc; poles fall along this swathe according to their position in the complex and their blocking temperatures, and the resultant path is interpreted as a migration of this zone away from the palaeopole at a rate of 1.3–3.0° Ma−1. The total swathe represents 10–20° of a.p.w. movement at 900–940 Ma; an isolated later (‘Y’) magnetisation may represent a later extension of the path at ca. 840 Ma. Two sets of magnetisations, a NW negative, predominantly hematite-held, and SSW negative, predominantly magnetite-held, are recognised in the gabbro-norite intrusions of the Bamble sector and are linked to radiometric events at 1090 and 1010 Ma. In the Brattön and Älgön norite-anorthosite bodies of west Sweden, demagnetisation trends and site mean directions define a short swathe of westerly negative directions linked to radiometric ages averaging ∼ 1000 Ma. Minor dolerite (hyperite) bodies intruded near the eastern margin of the Sveconorwegian belt possess predominantly steep positive and negative directions of magnetisation comparable to results from the Scania region at the southern margin of the belt. The collective palaeomagnetic data from the Sveconorwegian belt and its borders define a flattened anticlockwise a.p.w. loop with an amplitude of ∼ 70° and executed over the approximate interval 1050-840 Ma with the apex, or hairpin, defined by the Rogaland data at ca. 940 Ma. This loop correlates precisely with a loop defined by the uplift and cooling magnetisations from the Grenville terrain of the Laurentian Shield and shows that the Fennoscandian and Laurentian Shields were in juxtaposition between 1050 and 850 Ma with the two linear frontal zones disposed at a high angle to one another. These fronts were probably initiated in alignment, however, because they are disposed in this way on a primitive reconstruction derived from the pre-1190 Ma palaeomagnetic data. Break up and relative movements of the two shields occupied a short period between 1190 and 1050 Ma, following the Grenville-Sveconorwegian tectonism. It was associated with widespread rifting, dolerite intrusion and alkaline magmatism into the already stabilised parts of the shields.