Plutons in the 1.42 Ga Signal batholith provide an important case study for understanding the regional tectonic setting of Mesoproterozoic magmatism in the south-western United States and processes of emplacement for plutons far from active plate margins. Mesoproterozoic plutons in the Signal batholith were emplaced at ∼3 kbar and have a well-developed magmatic fabric which is subparallel to variably oriented Paleoproterozoic country rock foliations and shear zones, indicating that pluton emplacement was strongly influenced by crustal anisotropy. Solid-state deformation of Mesoproterozoic granites is best developed in shallowly dipping roof domains (40–60°), whereas in steep to vertical fabric domains, granites are generally undeformed and locally cross-cut older fabrics. This suggests that roof domains remained hotter and experienced greater thermal softening and subsequent deformation. Structural and kinematic study of three separate plutons in the Signal batholith indicate that pluton emplacement occurred in a regional contractional strain field, although local complexities suggest possible stress-field modification by pluton-related stresses. Evidence to support regional contractional strain during emplacement includes: (1) consistent dyke orientations throughout the batholith indicating a NNE extension and SE-NW shortening; (2) magmatic to solid-state fabric transition in thrust-sense deformation along the 40–60° dipping south-east margin of the Signal granite, including melt-filled shear zones and asymmetric K-feldspar porphyroclasts; and (3) syn-tectonic textures in contact metamorphic andalusite prophyroblasts. Regional variation in shortening direction from SE-NW to ∼NS during batholith emplacement may be related to pluton-emplacement stresses locally dominating over the relatively low deviatoric stresses of regional deformation. The main controlling factor for the geometry of pluton emplacement in the Signal batholith was Paleoproterozoic foliations and shear zones, which provided conduits for movement of magma into the middle crust. The flow of magma parallel to older structures may have been accommodated by a reduction in effective normal stresses by magma pressure and separation along the structural anisotropies. This model for anisotropy-influenced emplacement during weak regional contraction may be applicable to other ∼1.4 Ga plutons across SW Laurentia.