She had been widely touted as a future Democratic contender for the 2020 elections after a rousing speech at the Golden Globes earlier this month.
But she told InStyle "I've always felt very secure and confident with myself in knowing what I could do and what I could not.
"And so it's not something that interests me."
She gave the interview three weeks before picking up the Cecil B DeMille award for outstanding contribution to entertainment in early January, InStyle said.