blow/knock somebody's socks off

blow (one's) socks off

To thoroughly impress, overwhelm, or excite one. The show of support from everyone just blew my socks off. That movie really blew my socks off—I didn't expect it to be so good!
See also: blow, off, sock

knock (one's) socks off

To thoroughly impress, overwhelm, or excite one. The show of support from everyone just knocked my socks off. That movie really knocked my socks off—I didn't expect it to be so good!
See also: knock, off, sock
Farlex Dictionary of Idioms.

knock someone's socks off

 and knock the socks off (of) someone
Sl. to surprise someone thoroughly. (Fixed order. Of is usually retained before pronouns.) The exciting news just knocked my socks off! The news knocked the socks off of everyone in the office.
See also: knock, off, sock
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

blow/knock somebody’s ˈsocks off

(informal) surprise or impress somebody very much: With that dress and your new haircut you’ll knock their socks off!
See also: blow, knock, off, sock
Farlex Partner Idioms Dictionary

knock (someone's) socks off

Slang
To overwhelm or amaze.
See also: knock, off, sock
American Heritage® Dictionary of the English Language, Fifth Edition.
See also:
  • blow (one's) socks off
  • blow mind
  • blow one's mind
  • blow someone’s mind
  • blow someone's mind
  • blow your mind
  • blow your/somebody's mind
  • blow (one's) mind
  • blow someone/something off
  • blow off