"Ultimately Canada needs to move towards phasing out all non-essential plastics if we are going to truly reduce the very bad plastic legacy we are leaving for future generations of all life on this planet", Sarah King of Greenpeace Canada said in a statement.
"As early as 2021, Canada will ban harmful single-use plastics from coast to coast", Trudeau said.
The prime minister also said it's "tough trying to explain" to his children why "dead whales [are] washing up on beaches around the world, their stomachs jam-packed with plastic bags", Reuters reported.
The federal government has yet to release a full list of the items that will be banned.
"As parents, we're at a point when we take our kids to the beach and we have to search out a patch of sand that isn't littered with straws, Styrofoam or bottles".
Trudeau's government launched a new Ocean Plastics Charter during the G7 summit in Quebec back in 2018.
The non-binding Ocean Plastics Charter called on participating countries and the European Union to commit to making all plastics reusable, recyclable or recovered by 2030.
He said the volumes required to produce consumer single-use plastics are small and, while a ban may impact some end-product manufacturers in Eastern Canada, it likely won't affect the oil and gas sector in the West or the big industrial plastic manufacturers.
In Australia, Hobart has become the first capital city set to ban single-use plastics, including takeaway food containers and straws.
Eight years ago, the ACT banned single-use plastic shopping bags - and now the territory is taking aim at a range of other single-use plastics.
"We believe if you couple that growth with the proper collection, repurpose, reuse of plastics, it's going to continue to make the products more in demand".
This initiative is modelled on similar legislation passed previous year by the European Union and other nations.
Microplastics often come from larger plastics breaking down.
"Our fundamental belief is that globally, plastics will continue to grow and that we'll need multiple plants to be built year over year to enable that growth", he said in an interview.
About 3 million tonnes of plastic waste is thrown away each year in the country.
Mr Trudeau revealed the move less than five months before a national election in which climate change and pollution are among the top campaign issues.