Grieving's a Folly is an 1809 comedy play by the British writer Richard Leigh.

The cast included Henry Siddons as Mr Herbert, Harriet Siddons as Ellen, William Dowton as Sir Oliver Cypress, William Powell as Belford, John Bannister as Crape, John Henry Johnstone as O'Harrolan, Charles Mathews as Joe Thresher, Walter Maddocks as Jonathon, Jane Powell as Mrs Mordaunt and Frances Maria Kelly as Susan Woodburn.

The prologue was written and spoken by Edmund John Eyre.

It enjoyed a successful run and was published by Longmans the same year.

A second play by Leigh Where to Find a Friend was performed by the company in 1811.