The Captain America: The First Avenger star was stunned when Oscar winner Streep introduced herself and began doling out praise, and admits the meeting was a career highlight.
When asked to name her proudest moment of the past year, she tells Britain's InStyle magazine, "Meeting Meryl Streep."
Atwell recalls, "She knew who I was and came up to compliment me on a performance. She was so utterly charming and at that moment I thought, 'Yes, sanity does exist in this industry.' If, like her, I focus on what matters? Then I'll be fine."
The Brit is also proud to be making a name for herself in the movie industry, despite refusing to conform to Hollywood's size-zero trend.
She adds, "I've heard tales of directors offering their lead actress a plate of doughnuts just to test them. I was looking at footage of my Captain America audition the other day and thought, 'I've got a real paunch!' But it made me happy that I got the part because I was playing it right, not because I looked perfect."