Actress Meryl Streep accepts the Oscar for Best Actress for her role in "The Iron Lady" at the 84th Academy Awards in Hollywood, February 26, 2012.[Photo/Agencies]

Meryl Streep won the Oscar for best lead actress on Sunday for her portrayal of former British Prime Minister Margaret Thatcher in "The Iron Lady."

It was Streep's third Oscar, and her first in 30 years, although she has a record 17 nominations for the most coveted prize in the movie industry.

Streep's previous Oscars were for the 1979 film "Kramer vs. Kramer" and 1982's "Sophie's Choice". She had long been considered overdue for another Academy Award.

"When they called my name, I had the feeling I could hear half of America going, 'oh, come on,'" Streep said. "Oh, her again?"

"I look out there, and I see my life before my eyes, my old friend, my new friends," she said to the audience that had given her a standing ovation.

Streep, 62, is widely regarded as the best living movie actress, and most critics said she turned in her best performance ever as Thatcher.

She plays the feisty British leader both as a woman at the height of her powers in the 1980s, and as an old and lonely woman suffering from dementia in the present day.

Streep first appeared on screen in 1977 in "Julia" after having honed her craft at the Yale School of Drama and on stage.

She quickly became known for the depth and breadth of her characterizations, and for her gift with accents such as the Polish Holocaust survivor she played in "Sophie's Choice".

Dozens of other movies followed, ranging from romantic fare like "Out of Africa" and "The Bridges of Madison County" to biographical movies such as "Silkwood", and dramas like "Doubt" and the HBO television series "Angels in America" for which Streep won an Emmy.

"Mamma Mia!" joked Colin Firth, her co-star in the 2008 film "Mamma Mia!" who presented the award. "We were in Greece, I was gay, I probably fathered her daughter. "

"You are unreasonably good," Firth added. "Whatever role you play you raise the bar, making it a little more difficult for the rest of us."

In 2006, Streep changed direction to comedy, playing a ferocious fashion boss in "The Devil Wears Prada" and then camping it up in her first musical "Mamma Mia!".

She followed up with a dead-on impersonation of TV cook Julia Child in "Julie & Julia" and showed her flair for romantic comedy with "It's Complicated" opposite Alec Baldwin.