| Ladies of Letters | — | — | — | — |
| Lads' Army | ITV | reality television | 4 | 32 |
| Lady Killers | — | — | — | — |
| Lame Ducks | BBC Two | sitcom | 2 | 12 |
| Land Girls | BBC One | drama film | 3 | 15 |
| Land of Hope and Glory | British Broadcasting Corporation | — | — | 3 |
| Land of the Tiger | BBC Two | nature documentary | 1 | 6 |
| Landmark Sitcom Season | — | — | — | — |
| Landward | — | — | — | — |
| Lark Rise to Candleford | BBC One | drama television series | 4 | 40 |
| Last Chance Lottery | — | game show | — | — |
| Last Chance to See | BBC Two | — | 1 | 6 |
| Last Choir Standing | BBC One | reality television | 1 | 16 |
| Last Man Standing | BBC Three | reality television | 3 | 22 |
| Last of the Summer Wine | BBC One | sitcom | 31 | 295 |
| Last Tango in Halifax | BBC One | comedy drama, LGBT-related television series | 5 | 24 |
| Last Voices of World War 1 | — | documentary television program | — | — |
| Late Kick Off | BBC One | — | 5 | 64 |
| Late Night Horror | — | horror television series | — | 6 |
| Late Night Line-Up | — | — | — | — |
| Late Night Lycett | Channel 4 | talk show | — | — |
| Late Night Theatre | — | — | — | — |
| Late Starter | — | — | — | 8 |
| Later... with Jools Holland | BBC Two | music television | 51 | 295 |
| Laugh??? I Nearly Paid My Licence Fee | — | — | — | — |
| Law & Order: UK | ITV | police procedural, drama television series, legal drama | 8 | 53 |
| Lawless | — | thriller television series | — | 2 |
| Lazarus | Amazon Prime Video | thriller | — | — |
| Lazarus and Dingwall | — | — | — | — |
| Lead Balloon | BBC Four | sitcom | 4 | 27 |
| Leap in the Dark | — | anthology series | — | — |
| Learn With Sooty | — | — | — | — |
| Leave Us Kids Alone | — | reality television | — | — |
| Leaving | — | — | — | — |
| Lee Mack's All Star Cast | BBC One | comedy television series | 1 | 6 |
| Lee Nelson's Well Funny People | BBC Three | comedy television series | 1 | 7 |
| Lee Nelson's Well Good Show | BBC Three | comedy television series | 2 | 15 |
| Lefties | — | documentary film | — | — |
| Legends | Netflix | crime thriller film | — | — |
| Lego Masters | Channel 4 | reality television | — | — |
| Lemon la Vida Loca | ITV2 | — | 2 | 12 |
| Lemur Street | Animal Planet | documentary television program | 1 | 20 |
| Lena | British Broadcasting Corporation | variety show | 3 | 18 |
| Lena and Bonnie | — | — | — | — |
| Lena Zavaroni and Music | — | — | 1 | 6 |
| Lenny Blue | — | — | 2 | 4 |
| Lenny Henry in Pieces | British Broadcasting Corporation | comedy television series | 2 | 15 |
| Leonardo | Rai 1 | historical play, period drama film | 1 | 8 |
| Leonardo | BBC Children's and Education | drama television series | 2 | 26 |
| Les Dennis's Home Video Heroes | — | — | 2 | 60 |
| Let It Shine | BBC One | reality television | 1 | 3 |
| Let Me Entertain You | — | — | 1 | 6 |
| Let Me Entertain You | BBC Two | variety show | 2 | 40 |
| Let Them Eat Cake | BBC One | sitcom | 1 | 6 |
| Let There Be Love | — | sitcom | 2 | 12 |
| Let's Do Lunch with Gino & Mel | — | cooking show | 4 | 88 |
| Let's Get Gold | — | — | 1 | 3 |
| Let's Play | CBeebies | — | — | — |
| Let's Sing and Dance | — | talent show | — | — |
| Level Up | British Broadcasting Corporation | — | — | — |