A specially trained team has been tasked with investigating alerts raised by the British public who will review reports and take down violating adverts, in a bid to clamp down on potentially devastating misleading adverts.
Scam adverts often use fake celebrity images or endorsements to dupe people into buying false products and services, such as bitcoin trading schemes and diet pills.
The consumer champion dropped a campaign lawsuit against Facebook in January, after the social network agreed to donate £3 million to Citizens Advice in setting up the new scam advert prevention project.
Mr Lewis previously announced his intention to sue Facebook for defamation in a personal capacity in a groundbreaking lawsuit, following a raft of scam ads featuring his picture.
"The UK faces an epidemic of online scam ads - they're everywhere," the founder of MoneySavingExpert.com said.
"Yet disgracefully there's little effective law or regulation to prevent them, and official enforcement is poor to non-existent, as these criminals are usually based outside of the EU.
"That's why I sued for defamation, bizarrely the only law I could find to try to make big tech firms understand the damage their negligent behaviour has caused.
"Today should be the start of real improvement. The aim is to tap the power of what I'm dubbing 'social policing' to fight these scams.
"Millions of people know a scam when they see it, and millions of others don't.
"So now, I'd ask all who recognise them to use the new Facebook reporting tool, to help protect those who don't - which includes many who are vulnerable.
"Facebook's new dedicated team will then hopefully respond quickly to ditch the scammers."
The Citizens Advice Scams Action team is expected to help at least 20,000 people in the first year, the charity said.
It will also carry out scam prevention work to identify, tackle and raise awareness of online scams in the UK.
"We know online scams affect thousands of people every year," said Gillian Guy, chief executive of Citizens Advice.
"We're pleased the agreement between Martin Lewis and Facebook meant we could set up this dedicated service to give more help to people who have fallen victim to online scams."
Steve Hatch, vice president for Northern Europe at Facebook, said scam ads are "an industry-wide problem" caused by criminals and have "no place on Facebook".
"Through our work with Martin Lewis, we're taking a market leading position and our new reporting tool and dedicated team are important steps to stop the misuse of our platform," he explained.
"Prevention is also key. Our £3 million donation to Citizens Advice will not only help those who have been impacted by scammers, but raise awareness of how to avoid scams too.
"At a global level we've tripled the size of our safety and security team to 30,000 people and continue to invest heavily in removing bad content from our platform."