Eight of the 43 bodies that were surveyed said they didn’t use single-use cups in 2018. Campaigners welcomed this news but they said the 9.6 million cups ordered was too many.
BBC Wales through a Freedom of Information request showed a £71,000 fall in the amount of money public bodies spent in Wales on single-use cups.
Rebecca Colley-Jones, a trustee of the Chartered Institute of Waste Management, said: “Two million is a big decrease. It's very positive. These things don't happen overnight. You take it a step at a time. Perhaps what's happened over the last year or so is that people realise the consequences of it. Everyone will now have been getting used to a little inconvenience."
Cardiff University is one of the public bodies that has gone plastic free. A spokesperson added: "The phasing out of single-use plastics across the university is one of a number of measures that we've put in place to help build an inclusive, sustainable and resilient future for our community and to bring about environmental benefits not only to Cardiff and Wales but to the wider world.
"We are extremely pleased with the progress we've made over the past year, however we are not complacent and will continue to look at ways in which we can reduce our campus footprint."
Monmouthshire council said it stopped using plastics since 2018-19. Other public bodies have invested in biodegradable cups or they have been encouraging staff to re-use their cups.