Writing in the Daily Mail, Dr John Sentamu expressed concern over the "growing amount of inappropriate material" being accessed by children and young people on the internet.
Whilst endorsing the internet as a "wonderful educational tool", the Archbishop said it was important that children access the web in a "safe and controlled environment".
He said: "In our modern world parents have an increasingly hard time protecting their families from online dangers and it is right that we put proper protections in place.
"In our society there is a growing loss of innocence caused by increased sexualisation on TV, in films, music, magazines, even in the products on our supermarket shelves.
"We can see it in the cult of celebrity, the pressure to be thin, having to wear the right clothes or make up. The consumerist culture plays on our natural desire to fit in.
"However this loss of innocence can be harmful to our young people. We need to let children be children."
The Archbishop warned that pornographic sites were affecting young people's views of relationships, causing boys to see girls "simply as sex objects" and "putting pressure on girls to have sex earlier".
He said: "Whilst many children are easily or inadvertently accessing internet pornography, this is by no means the only danger. Indeed many websites portray extreme violence; promote self-harm and anorexia; or contain materials concerning suicide.
"Computer manufacturers and Internet Service Providers have a responsibility to make accessing such materials as difficult as possible.
"The need for us to preserve childhood is a responsibility that we should all want to uphold."
He called for opt-in filters, whereby harmful sites are automatically blocked from computers unless adults specifically opt in to have access to them.
The Government consultation on parental internet controls is due to close on Thursday. It follows an inquiry by a cross-party panel of MPs, which recommended that the Government initiate a formal review of opt-in filters.
The Archbishop further recommended that the Government put pressure on internet service providers (ISPs) to accelerate their plans to implement 'Active Choice' content filtering systems for new customers, and roll out 'single account' network filters that block porn from all devices connected to the same internet account.
"Let us urge the Government through this consultation to compel the ISPs, who make more than £3 billion a year from selling internet access services, to do what they can to protect our children," he said.
"The misery and heartache caused to British families is immeasurable."
The Government consultation can be accessed here