Government departments can no longer purchase single-use plastic straws, cups or cutlery from today.
The initiative also includes plans to cut waste in food and paper, and to improve efficiency in the use of water and energy.
All public bodies and schools have until the end of March to implement the new rules.
The public service spends €12 billion in procuring goods and services each year.
Announcing the new measures, Minister for Communications, Climate Action and the Environment Richard Bruton said the Government wanted to lead the way in showing that it was taking sustainability policies seriously.
The move comes after the European Parliament voted for a European Union-wide ban on single-use plastics in October.
Last January, the European Commission adopted its first ever Europe-wide strategy on plastics.
Under the plan, it is intended that all plastic packaging on the EU market will be recyclable by 2030.