happy as a clam

(as) happy as a clam

Very joyful and contented. Look at your sister out there! She's happy as a clam now that she's back in the starting lineup again. I know I'll be as happy as a clam once I get this stupid cast off my leg.
See also: clam, happy
Farlex Dictionary of Idioms.

*happy as a clam (at high tide)

 and *happy as a clam (in butter sauce); *happy as a lark; *happy as can be
contented; very happy. (*Also: as ~.) I've been as happy as a clam since I moved to the country. I don't need much. Just somewhere to live, some work to do, and a TV to watch, and I'm happy as a clam at high tide. Matthew was happy as a lark throughout his whole vacation. Bob was happy as can be when he won the lottery.
See also: clam, happy
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

happy as a clam

AMERICAN
If you are happy as a clam, you are very happy. Join the other kids. Do that, and before you know it you'll be happy as a clam.
See also: clam, happy
Collins COBUILD Idioms Dictionary, 3rd ed.

(as) happy as the day is ˈlong/as a ˈclam/as ˈLarry

(informal) very happy: Grandpa’s as happy as a clam helping the children to fly their kites.
See also: clam, happy, Larry, long
Farlex Partner Idioms Dictionary
See also:
  • (as) happy as a clam
  • clam
  • happy as the day is long/as a clam/as Larry
  • Larry
  • (as) happy as can be
  • (as) happy as a clam in butter sauce
  • (as) happy as the day is long
  • happy as the day is long
  • tide
  • cut back to