- MacAskill, Kenny
- MacKinlay, Craig
- Mackintosh, David
- Mackrory, Cherilyn
- Maclean, Rachel
- MacNeil, Angus
- Mactaggart, Fiona
- Madders, Justin
- Mahmood, Khalid
- Mahmood, Shabana
- Main, Anne
- Mak, Alan
- Malhotra, Seema
- Malthouse, Kit
- Mangnall, Anthony
- Mann, John
- Mann, Scott
- Marris, Rob
- Marsden, Gordon
- Marson, Julie
- Martin, Sandy
- Maskell, Rachael
- Maskey, Paul
- Masterton, Paul
- Matheson, Chris
- Mathias, Tania
- May, Theresa
- Mayhew, Jerome
- Maynard, Paul
- McCabe, Stephen
- McCaig, Callum
- McCallion, Elisha
- McCarthy, Kerry
- McCartney, Jason
- McCartney, Karl
- McDonagh, Siobhain
- McDonald, Andy
- McDonald, Stewart
- McDonald, Stuart
- McDonnell, Alasdair
- McDonnell, John
- McElduff, Barry
- McFadden, Pat
- McGarry, Natalie
- McGinn, Conor
- McGovern, Alison
- McInnes, Liz
- McKinnell, Catherine
- McLaughlin, Anne
- McLoughlin, Patrick
- McMahon, Jim
- McMorrin, Anna
- McNally, John
- McPartland, Stephen
- McVey, Esther
- Meacher, Michael
- Meale, Alan
- Mearns, Ian
- Menzies, Mark
- Mercer, Johnny
- Merriman, Huw
- Metcalfe, Stephen
- Miliband, Edward
- Millar, Robin
- Miller, Maria
- Milling, Amanda
- Mills, Nigel
- Milton, Anne
- Mishra, Navendu
- Mitchell, Andrew
- Mohindra, Gagan
- Molloy, Francie
- Monaghan, Carol
- Monaghan, Paul
- Moon, Madeleine
- Moore, Damien
- Moore, Robbie
- Moran, Layla
- Mordaunt, Penny
- Morden, Jessica
- Morgan, Nicky
- Morgan, Stephen
- Morris, Anne Marie
- Morris, David
- Morris, Grahame
- Morris, James
- Morrissey, Joy
- Morton, Wendy
- Mowat, David
- Mulholland, Greg
- Mullan, Kieran
- Mullin, Roger
- Mumby-Croft, Holly
- Mundell, David
- Murray, Ian
- Murray, James
- Murray, Sheryll
- Murrison, Andrew