| A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |
| From | Cost | Date | To | Cost | Date | ||
| MacKelsey | 1884 | 1885 | |||||
| MacLaren | D | Plymouth Argyle | £8,000 | 2 January 1965 | Southampton | £5,000 | 24 September 1966 |
| MacLaren | W S | Unknown | 24 June 1981 | Hibernian [Sco] Released |
Loan | 16 August 1982 8 October 1982 |
|
| Madden | L D | Sheffield Wednesday | Free | 15 August 1991 | Darlington | Free | 3 September 1993 |
| Maguire | J E | Willington | Fee Unknown | 8 November 1935 | Sunderland Hibernian [Sco] |
Guest Fee Unknown |
1944-45 14 April 1945 |
| Mahon | G | Juniors | NA | 1 August 1995 | Hereford United | Free | 12 July 1996 |
| Maierhofer | S | Rapid Vienna [Aus] | £1,800,000 | 31 August 2009 | Bristol City RB Salzburg [Aus] |
Loan £1,030,000 |
15 March 2010 23 August 2011 |
| Malcolm | K C | Juniors | NA | 1 March 1943 | Released | NA | October |
| Malone | S L | Juniors | NA | 1 July 2008 | Southend United Burton Albion Bournemouth |
Loan Loan £150,000 |
1 August 2009 22 October 2010 1 July 2011 |
| Malpass | A W | Wednesbury Old Athletic | Fee Unknown | 1 August 1891 | Retired | 1899 | |
| Mancienne | M I | Chelsea Chelsea Chelsea |
Loan Loan Loan |
27 October 2008 13 August 2009 26 August 2010 |
NA | ||
| Mannion | G P | Juniors | NA | 27 November 1957 | Norwich City | £17,000 | 31 August 1961 |
| Marcal | F | Olympique Lyon [Fra] | £1,800,000 | 6 September 2020 | Botafogo [Bra] | Free | 19 July 2022 |
| Mardenborough | S A | Coventry City | Free | 20 September 1983 | Cambridge United Swansea City |
Loan Free |
23 February 1984 24 August 1984 |
| Margreitter | G | Austia Vienna [Aus] | £2,250,000 | 24 August 2012 | Copenhagen [Den] Chesterfield 1FC Nurenburg [Ger] |
Loan Loan Free |
2 September 2013 11 September 2014 24 August 2015 |
| Marques | C F | Juniors | NA | 1 July 2020 | Belenenses [Por] | Loan | 31 August 2021 |
| Marr | A | Coventry City | Fee Unknown | 6 May 1913 | Gateshead | Free | 1914 |
| Marsden | C | Huddersfield Town | £250,000 | 11 January 1994 | Notts County | £250,000 | 15 November 1994 |
| Marsden | F | Accrington Stanley (1) | Fee Unknown | 29 January 1935 | Bournemouth & Boscombe Athletic | Fee Unknown | 9 May 1936 |
| Marsh | J | Unknown | 10 August 1936 | Newport County | Fee Unknown | 15 September 1936 | |
| Marsh | R | Unknown | Exeter City | 7 November 1941 | |||
| Marshall | A J | Ipswich Town | Loan | 12 November 2003 | NA | ||
| Marshall | B | Blackburn Rovers | £1,260,000 | 31 January 2017 | Millwall Norwich City |
Loan £1,530,000 |
31 January 2018 29 February 1924 |
| Marshall | G H | Southend United | Fee Unknown | 14 May 1919 | Walsall | Fee Unknown | |
| Marshall | J G | Norwich City | Fee Unknown | 29 April 1939 | Workington | Fee Unknown | August 1946 |
| Marshall | W H | Southport | Fee Unknown | 16 March 1928 | Port Vale | Fee Unknown | 15 March 1930 |
| Marson | F | Darlaston | Fee Unknown | 16 May 1923 | Sheffield Wednesday | Fee Unknown | cs1925 |
| Martin | D K | Belfast Celtic | £7,250 (combined) | 14 December 1934 | Nottingham Forest | Fee Unknown | 30 June 1936 |
| Martin | J C | Aberdare Athletic | Fee Unknown | 18 October 1923 | Reading | Fee Unknown | cs1924 |
| Martin | T | Newport County | Fee Unknown | 3 May 1930 | Swansea Town | Fee Unknown | 21 July 1932 |
| Martin | T W | Juniors | Fee Unknown | 1940 | Millwall | Guest | 1942-43 |
| Martinez | E | Arsenal | Loan | 10 August 2015 | NA | ||
| Mason | C | School | Fee Unknown | 1880 | Retired | May 1892 | |
| Mason | J | Blakenhall St Lukes | Fee Unknown | July 1885 | Willenhall Swifts | Fee Unknown | May 1891 |
| Mason | J | Worcester City | Fee Unknown | 17 January 1908 | 1909 | ||
| Mason | J | Cardiff City | £3,500,000 | 28 January 2016 | Burton Albion Colorado R [USA] Portsmouth MK Dons |
Loan Loan Loan Released |
23 August 2017 20 February 2018 31 August 2018 31 January 2019 |
| Mason | R H | Juniors | NA | 30 May 1953 | Chelmsford City | Free | 12 July 1962 |
|