Speaking at an event hosted by think-tank Theos, Williams said anti-capitalist demonstrators lacked clarity of purpose.
He called their message about capitalism in crisis "so general as to be undemanding".
"Rather like that episode in Father Ted where the priests demonstrate outside the cinema with a placard saying 'Down With This Sort of Thing'," said Archbishop Williams.
"I just feel we've got to do a bit better than that.
Dominic Gover | www.ibtimes.co.uk