Optically pumped magnetometer magnetoencephalography (OPM-MEG) data were acquired during a somatosensory task using a 192-channel OPM-MEG device which is adaptable to head size and robust to participant movement. This dataset contains data from individuals aged between 2 and 34 years. Analyses and descriptions of the dataset were published in eLife (https://doi.org/10.7554/eLife.94561.1) Defaced, T1-weighted MR images are provided for each participant. These were generated using an individualized template anatomy approach where age-matched template MRIs were warped to an optical 3D scan of each individual's head-shape. Data were compressed using zip on Windows. Matlab (2022b) scripts used for data loading and analysis can be found on (https://github.com/LukasRier/RierRhodes_2024_Neurodevelopmental_OPMMEG)