The Prime Minister is due to ask all the 52 leaders at the meeting to sign up to the Commonwealth Clean Oceans Alliance set up to help developing Commonwealth countries research and improve waste management.
Another £20m is to be spent to curb plastic and other environmental pollution generated by manufacturing.
Poor waste management is the single leading cause of plastics in the ocean, and improving waste infrastructure in developing countries will be a major focus of the CCOA, according to Downing Street.
The funding package was announced in a speech on Sunday (15 April) in advance of the 2018 Commonwealth Heads of Government Meeting, in which Theresa May also revealed the first countries to have joined the new Commonwealth Clean Oceans Alliance (CCOA).
The remaining £16.4 million ($23.5 million) will be devoted to improving waste management at a national and a city level to stop plastics entering the water, WWF-UK said.
The CCOA has been jointly set up by the United Kingdom and Vanuatu to drive action on plastic waste.
"As one of the most significant environmental challenges facing the world today, it is vital we tackle this issue so that future generations can enjoy a natural environment that is healthier than we now find it".
The UK public has shown passion and energy in the fight against plastic waste.
Missing south Kashmir Army man joins Hizb
Mir was posted in Bihar's Danapur. "Details are being ascertained", Defence spokesperson Colonel Rajesh Kalia told the daily. He had arrived at his native village on April 12 and had been missing since Saturday night, police officials said.
Researchers in the United States and Britain have accidentally engineered an enzyme which eats plastic and may eventually help solve the growing problem of plastic pollution, a study said Monday.
Her campaign comes in the wake of the Blue Planet II TV series which highlighted the issue of seaborne plastic pollution.
"It is a unique organisation with the strength and the commitment to make a difference".
Announcing the move on Saturday, May dubbed plastic waste a "scourge" on the world's oceans and promised to harness collective action from Commonwealth nations to "effect real change".
May hopes other Commonwealth nations will join the CCOA and follow in the footsteps of the United Kingdom on tackling plastic waste, by implementing measures such as a microbeads ban or plastic bag charges.
The NREL underscored the urgency of the work, pointing out that 8 million metric tons of plastic waste, including PET bottles, enter the oceans each year, creating huge man-made islands of garbage.
Scientists at the University of Portsmouth and the US Energy Department's National Renewable Energy Laboratory made a decision to focus on a naturally occurring bacterium discovered in Japan a few years ago.