The call comes as official figures reveal only a small proportion of offences are being punished, despite a countrywide escalation of the problem in recent years.
Data revealed under Freedom of Information rules shows Scottish councils were notified of a total of 207,960 incidents of illegally dumped rubbish from 2019 to this year, but only 2,467 fixed penalty notices were issued.
And just one conviction was secured out of 45 cases passed on to Crown prosecutors.
Scottish Liberal Democrat communities spokesperson Willie Rennie has called for increased fines for those who dispose of their waste illegally to help tackle destruction of the environment and massive annual clean-up costs for the public purse and private businesses.
Unauthorised disposal of rubbish is against the law, carrying penalties of imprisonment and fines up to £40,000. But littering and fly-tipping have increased significantly over the past decade, according to charity Keep Scotland Beautiful.
Incidents vary in scale from a single bag of household rubbish or a domestic appliance to industrial-level disposal of the likes of construction waste and tyres. The problem can cause serious harm to the environment, polluting land and water and posing a danger to wild animals and livestock.
It is also linked with serious and organised crime gangs and costs millions of pounds in clean-up costs each year, with Scots paying around £53 million annually for removal of illegal rubbish.
Around 26,000 tonnes of trash is unlawfully disposed of on public land annually, leaving Scottish authorities with a cleaning bill in the region of £11m.
Owners of private land that is targeted by dumpers, often repeatedly, are faced with footing their own work and costs.
Littering and fly-tipping incidents rose dramatically at the height of the Covid-19 pandemic, when municipal waste facilities were impacted by lockdown restrictions. Industrial action by council bin workers also saw a spike in illegal dumping.
Mr Rennie said: “From remote beauty spots to busy cities, these figures show that fly-tipping is a blight on our beautiful country. Not only that, but it can prove catastrophic for animals, plants and soil.
“The pandemic and the bin strikes disrupted refuse collections, but there is also a fundamental unfairness in the present system, which sees farmers and other owners left with the responsibility for clearing up waste, which has been dumped on their properties.
“We need to see local authorities using the powers at their disposal to clamp down on this disgusting behaviour and ensure that repeat offenders especially feel the full force of the law.”
Mr Rennie said his party would push for increased support for victims of illegal dumpers. He said: “Scottish Liberal Democrats also want to see increased support for farmers and those who bear the brunt of fly-tipping to help them with the clear up costs.
“This should use the proceeds of a new restitution order which hits offenders’ pockets hard. This could see courts able to require a contribution from offenders to a new national fund available to help victims.”
A Scottish Government spokesman said it was “determined to tackle the serious environmental and economic impacts that fly-tipping causes”. “We have already announced plans to more than double fines and are also looking at the possibility of extending the use of civil penalties to enforce offences,” the spokesman said.
“We will also be publishing a new litter and fly-tipping strategy in the new year, which will set how we will tackle these issues.”
The Crown Office has been approached for comment.