All of the city's school crossing patrols are to wear new coats bearing ChildLine's free, 24-hour helpline number - 0800 1111 - and its website address.
The scheme has been praised by ChildLine's chairman, Esther Rantzen, and will be launched by council leader Mike Storey on Thursday.
Cllr Storey said: 'I am delighted that Liverpool is helping the city's children and young people by developing this innovative idea.
'As a parent and a headteacher, I know how important it is that children are protected from harm and have somewhere to turn in times of need. Today's children face all kinds of pressures - having someone to talk to about them is vital.
'This scheme will also further enhance the work of our school crossing patrols, who already do a valuable job ensuring children get to and from school safely.'
Esther Rantzen said: 'I am absolutely delighted that Liverpool City Council has come up with this brilliant idea.
'A parent once said to me that there are two numbers that children should know - their home number and ChildLine's number.
'Now we have a new way to remind young children in Liverpool of ChildLine's free, 24-hour helpline number - 0800 1111.
'We know ChildLine has saved children's lives, and protected them from pain. We want to be sure that children don't suffer in silence, and that we are there for them if they need us.'
The ChildLine coats were the brainchild of Labour councillor Frank Prendergast. His colleague and local councillor Rose Bailey said: 'I am delighted to see this idea become reality - it is a coup for Liverpool.
'Every youngster in the city is precious and it is vital we do all we can to protect them.'
ChildLine North West's Outreach Co-ordinator, Sue Tabner, will be visiting schools in the area to talk to pupils about ChildLine's services