It comes as the House of Commons voted in favour of the Government's bill to ban the sale of tobacco products to anyone born after January 1, 2009.
NHS figures show £858,600 was spent on NHS Stop Smoking Services in Devon in 2023. The funding covers the delivery of services alongside the cost of pharmacotherapies such as nicotine replacement therapy.
Across England's local authorities, £37.9 million was spent helping people stop smoking through the NHS services.
John Waldron, policy and public affairs manager at Action on Smoking and Health, said: "Stop smoking services have been underfunded for many years and support a quarter of the numbers they did in 2010.
"As a central plank of our efforts to help smokers quit, this has long been unacceptable."
Mr Waldron added the Government's investment of £70 million into the services, alongside its "bold commitment" to phase out the sale of tobacco to those born after 2008 is welcome.
He said: "Through creating a smokefree generation and supporting current smokers to quit, we are on the path to ending smoking in this country for good."
The most recent data for April to December shows 744 (50%) of the 1,501 people in Devon who set a date to quit smoking were successful.
Across England, 54% of the 133,000 who set a date were able to give it up.
Rishi Sunak’s proposal to ban young people from ever being able to legally smoke tobacco cleared its first Commons hurdle last week, despite many Conservative MPs objecting to it.
MPs voted 383 to 67, with a majority of 316, to give the Tobacco and Vapes Bill a second reading.
The legislation, seen by the Prime Minister as a key part of his long-term legacy, would make it illegal to sell tobacco products to anyone born after January 1, 2009, with the aim of creating a "smoke-free" generation.
The Department of Health and Social Care estimates smoking is responsible for around 80,000 deaths annually, costing the NHS and economy an estimated £17 billion a year.
Health and social care secretary Victoria Atkins said smoking remains the UK’s biggest preventable killer.
"The truth is that there is no safe level of tobacco consumption. It is uniquely harmful and that is why we are taking this important action today to protect the next generation," she said.
"This bill will save thousands of lives, ease the strain on our NHS and improve the UK’s productivity."