The Oscar-winner called for “people in power” to “criminalise harmful content” as she picked up the leading actress gong at the TV awards.
The 47-year-old starred alongside her daughter Mia Threapleton in I Am Ruth which chronicles the relationship between a mother and child who is dealing with mental health pressures coming from the online world.
She told the ceremony: “I Am Ruth was made for parents and their children, for families who feel that they are held hostage by the perils of the online world, for parents who wish they could still communicate with their teenagers, but who no longer can.
“And for young people who have become addicted to social media and its darker sides: this does not need to be your life. To people in power, and to people who can make change: please, criminalise harmful content.
“Please eradicate harmful content, we don’t want it. We want our children back.
“We don’t want to lie awake, terrified by our children’s mental health.
“And to any young person who might be listening, who feels that they are trapped in an unhealthy world: Please ask for help. There is no shame in admitting that you need support. It will be there just ask for it.”
Her comments came as the House of Lords continued its scrutiny of the Online Safety Bill, which aims to tackle illegal and harmful content online.
Winslet stars as Ruth, a concerned mother who witnesses her teenage daughter Freya, played by 22-year-old Threapleton, retreating into herself as she becomes more consumed by the pressures of social media in the two-hour programme.
It is an instalment of the female-led drama anthology series I Am, created by filmmaker Dominic Savage.
I Am Ruth won the award for best single drama, while Channel 4’s Derry Girls was named best comedy.
Apple TV+ series Bad Sisters won in the best drama category, beating Sherwood and The Responder.
Claudia Winkleman was named best entertainment presenter for The Traitors, with the show itself winning the award for best reality show.
Other winners included a documentary about Sir Mo Farah which revealed the athlete had been trafficked to the UK as a child.
A royal edition of The Repair Shop featuring King Charles was named best daytime programme.
The ceremony on Sunday was hosted at the Royal Festival Hall by comedians Rob Beckett and Romesh Ranganathan.