This dataset comprises palaeointensity measurements from the Bourinot volcanic units (~505 Ma) and the Itabaiana dyke swarm (~525 Ma), with associated palaeomagnetic and rock magnetic metadata. The dataset covers Cambrian igneous units from two geographically distinct regions: the Bourinot volcanic sequence of Cape Breton Island, Nova Scotia (Avalonia), dated to ~505 Ma, and the Itabaiana dyke swarm of northeastern Brazil (Gondwana), dated to ~525 Ma. Together, these units sample magmatic rocks emplaced on separate palaeocontinental blocks during the early–middle Cambrian, providing geographically and tectonically independent constraints on geomagnetic field behaviour during this interval. The Excel file contains specimen-level palaeomagnetic and palaeointensity measurement data from Cambrian igneous units. It includes stepwise laboratory measurement records for individual specimens, comprising directional data (declination and inclination), magnetic moment and vector components, and associated experimental metadata. Each row represents a single laboratory measurement step within demagnetisation or palaeointensity experiments (e.g. IZZI-type Thellier protocols). The columns document specimen identifiers, experiment and method codes, instrument information, analysts, treatment conditions (thermal, alternating-field, and microwave where applicable), applied laboratory fields, measurement sequence, quality flags, and timestamps. Supporting metadata include citations, laboratory standards, and descriptive fields required for reproducibility and data reuse. The dataset is formatted to be compatible with established palaeomagnetic data standards and supports reconstruction of full experimental workflows for palaeointensity analysis.