So what's her latest role?
Arguably not one as exerting as some of her past sorties. Swinton has given her arthouse cinema credentials a fresh boost with her latest performance: sleeping in a fitted glass box at the Museum of Modern Art, New York.
What's that all about?
The 52-year-old actress, who won an Oscar in 2007 for her supporting role in crime thriller Michael Clayton, has reprised one her more unusual roles. Her somniferous performance debuted at the Serpentine Gallery in London in 1995. Now, she is lying peacefully on a mattress and pillow in a transparent, steel-rimmed chamber for a live installation entitled The Maybe for seven-hour stints. Her performance will run for a month on days randomly chosen and unknown even to staff.
So what does it all mean?
Good question. A plaque accompanying the performance gives little away, listing only the materials used and the artist's name.
But is it art?
You'll have to ask the punters. But fresh from a cameo in the video for David Bowie's latest single, "The Stars (Are Out Tonight)", and with two films set for release this year − sci-fi Snowpiercer and vampire romance Only Lovers Left Alive − it's understandable that Swinton wants to find an excuse for 40 winks.