| William Mathews | William Mathisen | William Matteuzzi |
| William Matthew Cavenaugh | William Matthew Flinders Petrie | William Maudit |
| William Maudit, VIII conte di Warwick | William Mauldin Hopkins | William Maurice Cowan |
| William Max Aitken | William Maximoff | William Maxwell |
| William Maxwell (scrittore) | William Maxwell Evarts | William Maxwell, V conte di Nithsdale |
| William May | William Mayer Flett | William Mayes Michaels |
| William Maynard | William Maze | William Méndez |
| William Mc Pherson | William McArthur | William McCabe |
| William McCadney | William McCahan | William McChesney Martin |
| William McChesney Martin, Jr | William McChesney Martin, Jr. | William McClellan Thornberry |
| William McCool | William McCrum | William McDonald |
| William McDonald (cestista) | William McDonald (politico) | William McDonald (vescovo) |
| William McDonald Wheeler | William McDonough | William McDougall |
| William McDowell-White | William McGann | William McGarvey Dudley |
| William McGill Kenville | William McGonagall | William McGregor |
| William McGregor Paxton | William McGuire Bryson | William McIlvanney |
| William McInnes | William McIntosh | William McIntosh (calciatore 1879-1973) |
| William McKell | William McKie | William McKinley |
| William McLachlan (pattinatore) | William McMahon | William McMaster Murdoch |
| William McMichael Shepherd | William McMillan | William McNamara |
| William McPherson Allen | William Meade Fishback | William Meade Lindsley Fiske |
| William Melling | William Mellor | William Melvin "Bill" Hicks |
| William Melvin Hicks | William Mendieta | William Menzies |
| William Meredith | William Meredith (poeta) | William Merle Laughlin |
| William Merriam | William Merriam Burton | William Merritt Chase |
| William Mervin McKinney | William Mervin Mills | William Merwin |
| William Merz | William Metzger | William Meyers |
| William Meynard | William Mezzanotte | William Michael Albert Broads |
| William Michael Curley | William Michael Daley | William Michael Harnett |
| William Michael Joensen | William Michael Masser | William Michael Morgan |
| William Michael Mulvey | William Michael Petrolle | William Michael Phillips |
| William Michael Rossetti | William Michael Varley | William Michael Wilds |
| William Michael Zabka | William Michaels | William Mikelbrencis |
| William Milbourne James | William Milbourne James (ammiraglio) | William Miles Dunn |
| William Miller | William Miller (attore) | William Miller (predicatore) |
| William Miller (storico) | William Milligan Sloane | William Mills Irwin |
| William Millton | William Milton | William Milton Breakenridge |
| William Mitchell | William Mitchell (economista) | William Mitchell Ramsay |
| William Moerner | William Moir | William Mokoena |
| William Moloney | William Molyneux | William Monahan |
| William Mong | William Montacute | William Montacute, I conte di Salisbury |
| William Montacute, II conte di Salisbury | William Montagu | William Montagu Douglas Scott, VI duca di Buccleuch |
| William Montagu, V duca di Manchester | William Montagu, VII duca di Manchester | William Montgomery Watt |
| William Moody | William Moore | William Moore (atleta) |
| William Moore (ciclista) | William Moore (ufologo) | William Morais |
| William Moreton | William Morgan | William Morgan (assicuratore) |
| William Morgan (educatore) | William Morgan (generale) | William Morgan (montatore) |
| William Morgan (regista) | William Morgan (vescovo) | William Morgan Cassidy |
| William Morganfield | William Morris | William Morris (attore) |
| William Morris (disambigua) | William Morris (imprenditore) | William Morris Agency |
| William Morris Davis | William Morris Endeavor | William Morris Hughes |
| William Morris Hunt | William Morris Meredith | William Morrison |
| William Morrison (chimico) | William Morrison, I visconte Dunrossil | William Morrissey |
| William Morrow | William Morrow Fechteler | William Morse Davidson |
| William Morton | William Morton (ciclista) | William Morton Kahan |
| William Morton Wheeler | William Moseley | William Moses Kunstler |
| William Mosforth | William Mosley | William Mosman |
| William Motherwell | William Motter Inge | William Moulton Marston |
| William Moultrie | William Mountfort | William Mueller |
| William Muir | William Muir MacKinnon | William Mulholland |
| William Mumler | William Mundy | William Mundy (compositore) |
| William Mundy (politico) | William Munford Tuck | William Murdoch |
| William Murphy | William Murphy (calciatore) | William Murray |
| William Murray, I conte di Dysart | William Murray, I conte di Mansfield | William Mutwol |
| William Myron MacDonald | William N'Gounou | William N'Jo Léa |
| William N. Jennings | William N. Lipscomb | William N. Pendleton |
| William N. Selig | William Nadylam | William Napier Shaw |
| William Naslund | William Nassau de Zuylestein, I conte di Rochford | William Nassau de Zuylestein, IV conte di Rochford |
| William Negri | William Neil | William Neil Leversee |
| William Nelson | William Nelson (lottatore) | William Nelson Pendleton |
| William Nestle | William Neville | William Neville, I conte di Kent |
| William Neville, I marchese di Abergavenny | William Neville, IV conte di Abergavenny | William Newcombe |
| William Neweham Montague Orpen | William Newman | William Newman-Norton |
| William Nichol | William Nicholas Selig | William Nicholas Stone Courtney |
| William Nicholson | William Nicholson (artista) | William Nicholson (chimico) |
| William Nicholson (sceneggiatore) | William Nicholson (scrittore) | William Nicholson Jennings |
| William Nicol | William Nieder | William Nierenberg |
| William Nigh | William Njobvu | William Njoku |
| William Njovu | William Nolan | William Nordhaus |
| William Norman Ferguson | William Norman Ligon | William Norris Powell |
| William Norval Craig | William Nott | William Nott-Bower |
| William Nunn Lipscomb | William Nunn Lipscomb Jr | William Nwadinobi Okpara |
| William Nye | William Nygaard | William Nylander |
| William Nylander (botanico) | William Nylander (hockeista su ghiaccio) | William O'Brien |
| William O'Brien, II conte di Inchiquin | William O'Connell | William O'Connor |
| William O'Dwyer | William O'Malley | William O'Neal |
| William O. Steele | William Oakley | William Odling |
| William Oefelein | William of Burnich | William of Burnick |
| William of Corbeuil | William of Malmesbury | William of Ockham |
| William of Rubio | William of Rubruck | William Ogburn |
| William Ogilby | William Ogilvy Kermack | William Okpara |
| William Olaf Stapledon | William Oliveira dos Santos | William Oliver |
| William Oliver (medico) | William Oliver Campbell | William Oliver Lipinski |
| William Oliver Stone | William Oloonkishu Yiampoy | William Onslow, IV conte di Onslow |
| William Onyeabor | William Orbit | William Orchard |
| William Orchard (architetto) | William Orlando Darby | William Orpen |
| William Orthwein | William Orville Ayres | William Orville Frizzell |
| William Osael Romero Castillo | William Oscar Guernesey Grut | William Osler |
| William Osler Health Centre | William Osorio | William Osula |
| William Otterwell Brady | William Oughtred | William Ouseley |
