André Clairon was a physicist at LNE-SYRTE, Observatoire de Paris, who made profound and continuing contributions to Time and Frequency Metrology. His work was recognized by several awards including the Rabi award in 1996 and the EFTF award in 2003. He had a global approach to research showing the same interest for experiment and theory, for fundamental science, technology and applications. Beyond T&F, he worked in several other fields such as atom interferometry, laser cooling of atoms, and laser development. His most prominent achievement is probably the pioneering realization of high accuracy atomic fountain frequency standards. International Atomic Time is now defined by such standards with relative uncertainties in the low 10-16. André Clairon was a wonderful colleague and collaborator, characterized by relentless curiosity, outstanding creativity and hard and rigorous work, while being always kind and modest. Let’s continue to be inspired by him!