Wizzard
"The character of Emma Peel was a direct mimic of The Black Widow character of the American Avengers, Honey West and Catwoman of the Batman stories."
Well, possibly; although I'm not aware of any sources to that effect, but this is unlikely to be why she wore a catsuit, since in 1965, Black Widow (who was still an Iron Man villain, rather than an Avenger) had only just gained a Black Canary-like costume after several appearances where she just wore a normal dress. She got the catsuit when she joined the Champions in the seventies. And Catwoman's costume at the time was a purple outfit with a skirt — the TV version wouldn't appear til the following year.
Honey West, meanwhile, debuted about five months before Mrs Peel's first appearance, which seems like some pretty narrow turnaround for it to have been an inspiration.
Edited by DaibhidC
I've always thought of Daredevil and Black Panther as being more Superheroes Wear Tights. If there's a reason why they're actually Rare Male Examples of this, unlike other tights-wearing superheroes, it's not really explained in the entries.