Rt Rev Stephen Cottrell admitted to looking at the images during his mid-teenage years, adding it was not something he was "particularly proud" of.
Addressing other peers in the House of Lords, the senior Anglican said on Tuesday: "When I was about 15, I had a Saturday job in a wood yard.
"The men who worked there often left their sleazy and - by today's standards, I suppose - fairly mild magazines lying around.
"When I was alone in the canteen and if I thought nobody could see me, I looked at those magazines."
Bishop Stephen also said the availability afforded to youngsters of extreme images through technology poses a "huge moral concern".
He warned "extremely warped and degrading attitudes" can result from the "persistent and pervasive" exposure to pornography.
Bishop Stephen spoke during a debate on a report by the House of Lord's communication select committee which called for further action on keeping children safe online.
While admitting the digital age does have benefits, he argued a change in the law is required "to lift it from the mire and misery" it was also creating.
Addressing the chamber, he said: "Although we are indeed growing up in the digital age, we lack maturity in the way we are governing and regulating and responding to this development.
"The digital age can be an age of cultural and intellectual and even moral prosperity but enlightened legislation based on sound and child-centred research is needed to lift it from the mire and misery that it is also creating."