a/one smart cookie

smart cookie

A clever and intelligent person. Don't underestimate Cindy's intelligence—she's one smart cookie!
See also: cookie, smart
Farlex Dictionary of Idioms.

a smart cookie

If someone is a smart cookie, they are clever and have good ideas. Anyone who made billions in the Russian oil industry is clearly a smart cookie. Helen's a pretty smart cookie — I trust her.
See also: cookie, smart
Collins COBUILD Idioms Dictionary, 3rd ed.

a/one smart ˈcookie

(American English, informal) a clever person with good ideas: Jed is one smart cookie. I’m sure he’ll do the right thing.
See also: cookie, one, smart
Farlex Partner Idioms Dictionary

smart cookie

n. a clever person. She’s really a smart cookie if you give her a chance.
See also: cookie, smart
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions
See also:
  • a smart cookie
  • smart cookie
  • (one) smart apple
  • cookie
  • get smart
  • get smart (with one)
  • get smart with someone
  • one smart apple
  • (as) smart as paint
  • smart