Massimilla "Milla" Baldo-Ceolin (12 August 1924, Legnago, Italy – 25 November 2011) was an Italian particle physicist.

The discovery of the proton and neutron antiparticles led Baldo-Ceolin to co-discover antilambda, the first antihyperon, with Derek Prowse after a 1957 conference.

She entered the NUE experiment at CERN, where she worked within Helmut Fraisser's team to determine a value for the Weinberg angle.

This collaboration used a liquid deuterium bubble chamber to explore neutrino interactions with protons and neutrons.

In 1998, she initiated the series of international workshops on neutrino telescopes at the Istituto Veneto di Scienze, Lettere ed Arti.