I've been thinking about identical twins in literature and I decided to make a list. There's no real point to it, except that I think there's a higher than usual number of redheads among them.
Tom and Pat Bartlett
Time For the Stars by Robert Heinlein
Hair: Not sure, but not red
Castor and Pollux Stone
The Rolling Stones by Robert Heinlein
Hair: Red, I believe
Sandy and Dennys Murray
A Wrinkle in Time interalia by Madeleine L'Engle
Hair: No idea. In fact, I'm not even sure they're identical.
Elladan and Elrohir, sons of Elrond
Lord of the Rings by JRR Tolkien
Brent and Stuart Tarleton
Gone With the Wind by Margaret Mitchell
Fred and George Weasley
Harry Potter books by JK Rowling
Jessica and Elizabeth Wakefield
Sweet Valley High sort of by Francine Pascal
And they were the only girls I could think of.
Who did I miss? Looking for identical twins here, so please don't bring up the Bobbsey Twins.
[Edited to correct spelling of "Bobbsey"]
[Edited again to correct factual error that nobody called me on]