In her acceptance speech, Hudson said tearfully, "Oh my God! I have to just take this moment in. I can't believe this - I didn't think I was going to win. Look at what God can do!"
She previously won a Golden Globe for the same role of a singer in a 60's R&B group who is pushed aside when someone more glamourous (Beyonce Knowles) comes along. The story is inspired by the real-life Supremes.
In the previous week, Hudson celebrated her success up to the Academy Awards at her family's church.
"I don't do clubs. I don't drink. I don't smoke," Hudson told a boisterous crowd at Progressive Baptist Church on Chicago's south side on Monday night. "I'm not having no club party; I better have a praise party."
Hudson, 25, headlined a gospel concert, "An Evening of Praise With Jennifer Hudson", accompanied by the acclaimed Soul Children of Chicago.
"It's an exciting time because the city is so rich in the gospel tradition," said audience member Brenda Morgan. "It's a great night. We're so proud of Ms Hudson."
Hudson first attracted attention as one of the finalists on the third season of the FOX reality/talent-search television series American Idol and stars.
After seeing Hudson's performance on the film, American Idol judge Simon Cowell taped a congratulatory message to her, which aired on The Oprah Winfrey Show.
