|Jack Lemmon||Felix Ungar|
|Walter Matthau||Oscar Madison|
|Monica Evans||Cecily Pigeon|
|Carole Shelley||Gwendolyn Pigeon|
When fussy Felix becomes suicidal over his impending divorce, he accepts an offer to move in with his best friend, messy Oscar . Felix drives Oscar crazy with his obsession over his soon-to-be ex. Oscar tries to get him out of his funk by arranging a double date with two wacky British neighbors, Cecily and Gwendolyn . When the plan backfires and Felix grows even more despondent, his friendship with Oscar is put to the test.