| Lawless | 2012 | — | — |
| Lawson | 2009 | — | — |
| Lay It on The Line | 12 January 2012 | — | — |
| Layers | 1 March 2011 | — | — |
| Leaf Hound | 1969 | — | — |
| Lean Logic | 18 May 2020 | — | — |
| Leftfield | 1989 | — | — |
| Lesbian Bed Death | 2004 | — | — |
| Let Loose | 1987 | — | — |
| Level 42 | 1980 | — | — |
| Levellers | 1988 | — | — |
| Liam Frost and the Slowdown Family | 2003 | — | — |
| Lieutenant Pigeon | 1972 | — | — |
| LIFE | 1 January 2013 | — | — |
| Lifeless | 2006 | — | — |
| Lighthouse Family | 1993 | — | — |
| Likes Lions | 15 November 2009 | — | — |
| Lionheart | 1980 | — | — |
| Lionrock | 1991 | — | — |
| Little Comets | 2008 | — | — |
| Little Fears | 1 October 2011 | — | — |
| Liverpool Echo | 1973 | — | — |
| Living Legends | 1981 | — | — |
| Livingston | 2002 | — | — |
| Lloyd Cole and the Commotions | 1982 | — | — |
| Loathe | 2014 | — | — |
| Locean | 2013 | — | — |
| Lock Up | 1998 | — | — |
| London Cowboys | 1980 | — | — |
| London Grammar | 2009 | — | An English indie pop and electronic trio formed in Nottingham, England, in 2009. |
| Long Fin Killie | 1993 | — | — |
| Looper | 1998 | — | — |
| Los Bitchos | 2017 | — | — |
| Lowen | 2017 | — | — |
| Lunar Bird | 1 May 2017 | — | — |
| Lunar Mantra | 2013 | — | — |
| Lvcifyre | 2007 | — | — |
| Lychgate | 2012 | — | — |
| Lyman Alpha Blob | 3 February 2014 | — | — |
| Lyrian | 2006 | — | — |
| LÄYKES | 1 January 2017 | — | — |
| M People | 1990 | — | — |
| M-pire of Evil | 2010 | — | — |
| M.I.6 | 1 October 2011 | — | — |
| Macabre Omen | 1994 | — | — |
| Madam | 2004 | — | — |
| Madness | 1976 | — | English pop/ska band |
| Mafafi | 2005 | — | — |
| Magazine | 1977 | — | — |
| Mage | 2010 | — | heavy rock band from Leicestershire, UK |
| Magenta | 2001 | — | — |
| Magna Carta | 10 May 1969 | — | UK folk rock group |
| Male Bonding | 2007 | — | — |
| Mallory Knox | 2009 | — | — |
| Mammoth Weed Wizard Bastard | 2014 | — | — |
| Man | 1968 | — | psychedelic band from Wales |
| Man Must Die | 2002 | — | — |
| Manfred Mann’s Earth Band | 1971 | — | — |
| Mania | October 1981 | — | — |
| MANIA | 2022 | — | — |
| Manic Street Preachers | 1986 | — | — |
| Manufactured Romance | 1979 | — | — |
| Marconi Union | 2002 | — | — |
| Marillion | 1979 | — | British progressive rock band |
| Marion | January 1993 | — | — |
| Mark–Almond | 1970 | — | — |
| Marmalade | 1966 | — | 60’s band |
| Marmozets | 1 June 2006 | — | — |
| Martin Stephenson and the Daintees | 1982 | — | — |
| Maruja | 2014 | — | — |
| Masiro | 2011 | — | — |
| Massive Attack | 1987 | — | — |
| Massive Violins | 2010 | — | — |
| Matchbox | 1971 | — | — |
| Max Raptor | 2006 | — | — |
| Maxïmo Park | 2000 | — | English alternative rock band |
| May Blitz | 1969 | — | — |
| Maybeshewill | 2005 | — | — |
| Mayfield's Mule | 1968 | — | — |
| McFly | 2004 | — | English pop band |
| Mega Emotion | 2013 | — | — |
| Mega Happy | 2017 | — | — |
| Memoriam | January 2016 | — | — |
| Menace | 1976 | — | — |
| Mesh | 1991 | — | — |
| Metabolist | 1977 | — | — |
| Metronomy | 1999 | — | — |
| Michael Moorcock & the Deep Fix | 1975 | — | — |
| Midas Fall | 2 August 2008 | — | — |
| Midnight Bonfires | 20 January 2011 | — | — |
| Midnight Configuration | 1993 | — | — |
| Midside | 1 April 2016 | — | — |
| Mighty Baby | 1969 | — | — |
| Mike + the Mechanics | 1985 | — | — |
| Mike TV | 2008 | — | — |
| Milltown Brothers | 1989 | — | — |
| Ministers 4 Justice | 2010 | — | — |
| Minor Victories | 2015 | — | — |
| Minus the Intention | 23 September 2009 | — | — |
| Miranda Sex Garden | 1988 | — | — |