Beach Buddies, established in 2006, co-ordinates weekly operations around the Isle of Man's coast.
A spokesman said the cash will mean the organisation can "expand on its work" which includes launching an educational programme in the coming year.
The government awarded the grant and said its work had "encouraged more people to use the outdoors".
The island's environment department said Beach Buddies, which has about 7,000 volunteers, had complemented several government strategies which also included growing visitor numbers.
Beach Buddies organiser Bill Dale said: "We now believe they [the beaches] are the tidiest in Europe."
New initiatives also include more bins at various beauty spots around the island.
It also aims to establish an online litter hotline where the public can report problems.

Nicole Clark used her mother Avril Stewart's bank details to set up online accounts.
The 30-year-old, from Woodside, admitted stealing the money between 8 August and 26 August last year.
Depute fiscal Robbie Brown told Perth Sheriff Court that the accused's mother had not recouped any of the stolen money.
Sheriff William Wood deferred sentence for the preparation of social work reports.

Richard Di Natale, head of the left-wing Australian Greens, argues reducing hours would boost productivity and allow workers more time with family.
Mr Di Natale said he was not suggesting a specific model, but workers would need to be guaranteed adequate income.
Australia's two major parties have not commented on the proposal, but it has drawn criticism from an economist.
In the dark days of the 19th Century, many workers in industrialised nations considered themselves lucky if they got Sunday off. The achievement of a 40-hour week with Saturday and Sunday off for many was a major landmark for the labour movement.
But some have tried to go further.
In 2008, about 17,000 government officials in the US state of Utah started working four 10-hour days in a bid to cut costs. The experiment didn't last: the five-day week was reinstated in 2011. Other US states have also toyed with the idea.
The Gambia recently scrapped its four-day working week, which had been designed to allow people more flexibility on Fridays.
But what is the ideal working week, and could the four-day week become more widespread?
Read more: How shorter weeks have worked elsewhere
Mr Di Natale said he wanted to start a national conversation on the future of work.
"It's time we recognised there are big questions we're not asking ourselves. What sort of society do we want to be?" he told the Australian Broadcasting Corp (ABC).
"We have some many people in this country who are working more hours than they should."
He said Australia could follow other countries in trialling a social security safety net to guarantee adequate income.
Economist Saul Eslake said he did not support the proposal, comparing it to France's 35-hour working week.
"The French are good at many things, but economic management is not one of them," he told the ABC.
"Their economy has grown at barely more than 1% per annum over the past seven years."
A beach clean-up charity has been given a £30,000 grant to help keep Manx beaches the "tidiest in Europe".
[NEXT_CONCEPT]
A Perthshire woman lost £2,020 she had stolen from her mother gambling at an online casino, a court was told.
[NEXT_CONCEPT]
Australia should consider adopting a four-day working week or a six-hour working day, a political leader says.