A sustainable transformation of white phosphorus (P₄) into chemicals of higher value is one of the key aspects in modern phosphorus research. Even though the chemistry of P₄ has been investigated for many decades, its chemical reactivity towards the simplest electrophile, the proton, is still virtually unknown. Based on quantum-chemical predictions, we report for the first time the successful protonation of P₄ by the Brønsted acid H[Al(OTeF₅)₄](solv). Our spectroscopic results are in agreement with acid-mediated activation of P₄ under protonation of an edge of the P₄-tetrahedron and formation of a three-center two-electron P–H–P bond. These investigations are of fundamental interest as they permit the activation of P₄ with the simplest electrophile as a new prototype reaction for this molecule.