The Bridget Suite is a series of undeformed, hornblende-bearing intrusions forming a ~150 km-long northwest trend within the northeastern Pilbara Craton. The trend is parallel to the c. 2.76 Ga Gregory Range Suite, which has A-type magmatic affinity, and to the Paleoproterozoic suture zone between the Percival Lakes Province and the Rudall Province. The Bridget Suite comprises numerous small plutons, stocks and dykes of hornblende- and clinopyroxene-bearing monzodiorite, monzonite, and monzogranite, commonly with trachytic textures. The intrusions are highly magnetic and can be identified readily in aeromagnetic images. However, the genesis of this distinct magmatic suite is poorly understood. Here we report new geochronology and geochemistry to better constrain the timing, petrogenesis, metallogenic fertility, and geodynamic setting of the Bridget Suite. The SHRIMP U–Pb zircon dating of a quartz monzonite collected from the largest Bridget Suite intrusion, in the Mosquito Creek Basin, yielded an igneous crystallization age of 1790 ± 7 Ma. The sample also contains xenocrystic zircon cores dated at 3352–3162 and 2879–2688 Ma, which are similar to ages of exposed igneous rocks in the East Pilbara Terrane, including the Emu Pool, Cleland and Split Rock Supersuites, and the Bamboo Creek Member of the Hardey Formation in the overlying Fortescue Basin. The abundant xenocrystic zircon cores are consistent with the hydrous nature of the Bridget Suite, as indicated by the presence of ubiquitous hornblende phenocrysts and low zircon saturation temperature of 700–740 °C. The crystallization age of 1790 ± 7 Ma indicates that the Bridget Suite is the youngest felsic magmatism in the Pilbara Craton. This suite is contemporaneous with the Yapungku Orogeny and emplacement of the 1804–1762 Ma Kalkan Supersuite in the Rudall Province, the main phase of the Capricorn Orogeny and emplacement of the Moorarie Supersuite in the Gascoyne Province, and deposition of the Ashburton Basin along the northern margin of the Capricorn Orogen. Based on the new geochemical data, the Bridget Suite appears to be an evolved, hydrous, and oxidized magmatic suite ranging from monzodiorite, monzonite to quartz monzonite. The suite is more alkaline and has higher Sr, Ba and Rb concentrations than all Archean granitic rocks in the Pilbara Craton. It is also metaluminous, belongs to the high-K to shoshonite series, and has high Sr/Y (35–83) and Eu/Eu* (0.85–0.97), both of which increase with increasing SiO2. The magmatic evolution of the suite is interpreted to involve suppression of plagioclase crystallization and promotion of hornblende crystallization in hydrous magma. The Bridget Suite may have originated from a mantle source, as indicated by higher Mg# (>50) and Cr (>25 ppm) in the most primitive samples, compared with partial melts of mafic lower crust. The suite is geochemically similar to K-rich porphyries at the Ok Tedi and Northparkes porphyry Cu-Au deposits, two well-known porphyry deposits in post-collisional setting, and likewise may be prospective for Cu-Au. We propose that the Bridget Suite was derived from metasomatized mantle beneath the eastern Pilbara Craton in an intraplate setting, and that the trigger for melting was likely related to Paleoproterozoic accretion of Percival Lakes Province onto east Pilbara Craton. The suite was likely emplaced along a pre-existing crustal-scale structure initiated during the c. 2.76 Ga east-west rifting of the Pilbara Craton, as marked by the Gregory Range Suite.