From Longman Dictionary of Contemporary Englishas pleased as punchas pleased as punchHAPPY old-fashioned very happy He’s as pleased as punch about the baby. → punch
Examples from the Corpus
as pleased as punch• He was a strong, healthy lad and as pleased as punch to be working with Dad.• He had landed a contract as pleased as Punch, and I made a feast for his friends.• He's as pleased as punch about the baby.as pleased as Punchas pleased as Punchold-fash very happy He’s as pleased as Punch about the baby. → Punch 