The 42-year-old actress - who has five-year-old twins Hazel and Phinnaeus, and son Henry, three, with her cameraman husband Daniel Moder - apparently turned to the religion while filming her latest movie `Eat Pray Love` in India last year.
She told Elle magazine: "I`m definitely a practising Hindu. Golly, I`ve been so spoiled with my friends and family in this life. Next time I want to be just something quiet and supporting."
Julia now often visits temples to "chant, pray and celebrate".
In `Eat Pray Love` - which is based on a memoir by US writer Elizabeth Gilbert - Julia plays a divorcee who decides to travel the world, before finding love in Bali.
During filming in India last year, Julia completely immersed herself in the Hindu culture and was "astounded" during a visit to the Taj Mahal.
The screen beauty was apparently "astounded" by the white marble structure, which is the most famous mausoleum on the globe and listed as one of the "seven wonders of the modern world".
At the time, a source said: "Julia was breathless, absolutely astounded by the Taj. She looked on in wonderment as her guide explained the intricate patterns and designs on the marble surface.
"The Taj is a legendary symbol of love and hopefully the monument will be an inspiration to her for her latest film."