La Poste’s Michel Foucault centenary stamp entered general sale on 19 October 2026 after first-day sales on 16–17 October. Louis Genty created, engraved and laid out the €2.25 international-letter stamp.

The 30 × 40.85 mm stamp was printed in intaglio with a run of 495,000. The design places Foucault before the Collège de France. Genty’s signing session at Le Carré d’Encre was announced for 16 October, 10:30–12:30.