Blanchett is completely non-religious.
Blanchett would probably be considered liberal for her one pet political issue--environmentalism.
Cate Blanchett, born Catherine, was born and raised in Melbourne, Australia.
Blanchett is among the minority of uber-famous, Academy Award winning actors with quite literally no information on her religious opinions, upbringing or even a bit of spiritual musing. Only a couple of things beyond the MySpace "Christian-other" tag merit mention.
First, her late father was an American of French descent so it's possible that there is some Catholic heritage there. However, her mother, as Blanchett describes, is Australian of "convict descent" meaning her ancestors were dropped off in Australia by the British when it was solely used to house criminals.
Second, Blanchett attended a high school of sorts called the Methodist Ladies College (MLC) in Melbourne, Australia. But Blanchett has described the school as "progressive" and "feminist." It certainly doesn't have the ring of traditional religion.
Regardless, she's got the online profile of a non-religious person. Feel free to dispute in the comments if you've got any information.
Carbon tax Cate
Politically, Blanchett seems fixated on one single issue–environmentalism. Her passion for this topic has inspired her to speak out about various problems, and their solutions. She has outfitted her Australian mansion with solar power and other eco-friendly innovations, and she has become an ambassador for the Australian Conservation Foundation, hoping to encourage Australians to collectively act on environmental concerns.
The biggest controversy of her political career came when she endorsed a Carbon Tax in Australia. The tax would charge polluting industries per ton of carbon they release into the atmosphere. Blanchett was criticized by Australian conservatives and some media for being a wealthy woman who would likely not feel the effects of additional taxes. She said:
I'm not really surprised by the reactions from people on the other side of the debate. People are entitled to their opinion… Everyone will benefit if we protect the environment. There is a societal cost of increased pollution and that's what I'm passionate about as a mother. That's where it gets me in the gut.
Always glad to see a little passion here at the Hollowverse.