| Name | Book/story/stage title | Notes
|
| Lake, Jack | Psmith Journalist | A gang member
|
| Lakenheath, Lady | Ukridge Rounds a Nasty Corner | A widow, preparing her husband's memoirs
|
| Lakenheath, Millicent | | Lady L.'s niece
|
| LaMarr, Babe | Sitting Pretty | A chorus girl
|
| Lanchester, Mr | The Story of Cedric | A cab driver
|
| Landseer, Mr | Full Moon | Alias of Bill Lister
|
| Lang | The Head of Kay's | Boy at Eckleton College
|
| Langridge, Mr | A Corner in Lines | Form master at Wrykyn College
|
| Lattaker, George | Rallying Round Old George | A young man, rallied around
|
| Lawlor, B. N. 'Boko' | The Long Arm of Looney Coote | A parliamentary candidate
|
| Lawrie, Mr | A Prefect's Uncle | Sixth form master at Beckford College
|
| Leach, Mr | Not George Washington | Cashier at the Moon Assurance Company
|
| Leather-Twigg, J. R. | | Know as 'Shoeblossom', a boy at Wrykyn College
|
| Le Brocq, Jeanne | Rough-hew them how we will | Waitress at Bredin's Parisian Café and Restaurant
|
| Lee, Mrs | The Prize Poem | Infirmary assistant at St. Austin's College
|
| Lefty | | A member of Buck McGinnis's gang
|
| Lehman, Fanny | Barmy in Wonderland | Wife of Joe Lehman; ex-juggler
|
| Lehman, Joe | Barmy in Wonderland | A stage producer
|
| Leicester, Mr | Personally Conducted | A weak house master at Beckford College
|
| Leigh, Tom | Love Among the Chickens | Farmer in Up Lyme
|
| Leonard, Daisy | Uneasy Money | Guest of Nutty Boyd at Geisenheimer's
|
| Leuthold | William Tell Told Again | A Swiss guard
|
| Levitsky, I. G. | | Co-executive of Perfecto-Zizzbaum Motion Picture Corp
|
| Liggett, Renshaw | Concealed Art | A man
|
| Linton, Charles J. | | Boy at Wrykyn College
|
| Lippett, Claire / Clara | Sam the Sudden | Housekeeper to Kay Derrick and Matthew Wrenn
|
| Lippett, Martha | Sam the Sudden | Claire's mother, housekeeper to Willoughby Braddock
|
| Lippincott, J. Bromley | Barmy in Wonderland | Attorney-at-law
|
| Liss | Homoeopathic Treatment | Boy at Wrykyn College
|
| Lister, Bill | Full Moon | Artist and pub owner
|
| Little, Mortimer | The Inimitable Jeeves | Lord Bittlesham before gaining the title
|
| Little, Richard (Bingo) | | A young man who finally settles down
|
| Llewellyn, Grayce | | Ivor's wife, an ex-actress
|
| Llewellyn, Ivor | | A motion picture magnate
|
| Long Otto | | Member of the Groom Street gang
|
| Lorimer | A Prefect's Uncle | Boy at Beckford College
|
| Lucas | Blenkinsop's Benefit | Boy at Beckford College
|
| Lunt, Freddie | Ukridge's Accident Syndicate | An injured man
|
| Lynn, Sir Claude | Something Squishy | Suitor of Bobbie Wickham
|