M
MacDougall brothers
- Gil MacDougall, Balmain Tigers and Western Suburbs Magpies NSWRFL player and father of Adam, Ben, Scott, and Luke
- Adam MacDougall (born 1975), Australian international and Sydney Roosters, Newcastle Knights and South Sydney Rabbitohs NRL player
- Ben MacDougall (born 1977), Manly-Warringah Sea Eagles, Melbourne Storm, Newcastle Knights NRL player
- Scott MacDougall (born 1980), St George Illawarra NRL player. [7]
- Luke MacDougall (born 1982), Newcastle Knights and South Sydney Rabbitohs NRL player
- Garry MacDougall (born 1938) St George
- Graeme MacDougall (born 1940) St George, Australian Wallabies (1961–62), Balmain Tigers
- Stuart MacDougall (born 1947) St George, Australian Wallabies (1973–76)
Maddison brothers
- Ken Maddison (born 1946), Australian international and St. George/Cronulla NSWRFL player
- Keith Maddison, St. George NSWRFL player
Malone/Renouf family
- Steve Renouf (born 1970), Australian international and Queensland Origin representative. Brisbane Broncos NRL and Wigan SL player; uncle of Donald
- Donald Malone (born 1985), North Queensland Cowboys NRL player; nephew of Steve [8]
Mann family
- Don Mann, New Zealand international player; father of Duane and Don Jr
- Duane Mann (born 1965), New Zealand & Tongan international player, Warrington RLFC player; son of Don
- Esau Mann, Tonga international player
- Don Mann, Jr. New Zealand Warriors football manager; son of Don
- George Mann, New Zealand & Tongan international; cousin of Duane
Mannah brothers
- Jon Mannah (1989–2013) Cronulla-Sutherland Sharks NRL player
- Tim Mannah (born 1988) Parramatta Eels NRL player
Mara family
Maranta family
- Barry Maranta, co-founder of the Brisbane Broncos
- Lachlan Maranta, Brisbane Broncos NRL player – Father is Brett Plowman, Brisbane Broncos Player
March twins
- David March (born 1979), Wakefield Trinity and York player
- Paul March (born 1979), Wakefield Trinity and York player
Martyn family
- Mick Martyn, Great Britain international, older brother of Thomas Martyn, and uncle of Tommy Martyn
- Thomas Martyn, England international, younger brother of Mick Martyn, and father of Tommy Martyn
- Tommy Martyn, Ireland international, son of Thomas Martyn, and nephew of Mick Martyn, father of Shay Martyn
- Shay Martyn, St Helens player, son of Tommy Martyn, grandson of Thomas Martyn
Mata'utia brothers
- Peter Mata'utia (born 1990), Samoan international, Newcastle Knights, St. George Illawarra, Leigh, and Castleford player
- Chanel Mata'utia (born 1992), Newcastle Knights player
- Pat Mata'utia (born 1993), Newcastle Knights player
- Sione Mata'utia (born 1996), Australian and Samoan international, Newcastle Knights and St. Helens player
A cousin, Masada Iosefa (1988–2021), was a Samoan international who played for Penrith and the Wests Tigers.
May brothers
- Tyrone May (born 1996), Samoan international, Penrith Panthers, Catalans Dragons & Hull KR player
- Taylan May (born 2001), Penrith Panthers player
- Terrell May (born 1999), Sydney Roosters Senior Representative player
McCabe brothers
- Paul McCabe (born 1959), Australian international and Queensland representative player
- John McCabe, Queensland representative player
McCarthy family
- Bob McCarthy, Australian international and South Sydney NSWRFL player
- Darren McCarthy, Canterbury-Bankstown NSWRL player
- Troy McCarthy, Gold Coast Chargers NSWRL Player
McLean family
- Willie McLean (born 1973), North Sydney Bears, father of Jesse & Casey
- Jesse McLean (born 2005) penrith Panthers NRL player
- Casey McLean (born 2006) penrith Panthers NRL player
- Alex Chan (born 1974), Parramatta Eels, Melbourne Storm & Catalans, brother-in-law of Willie
McClennan family
- Mike McClennan, New Zealand-born St. Helens RFL coach; father of Brian
- Brian McClennan, New Zealand-born Leeds Super League coach; son of Mike
McCormack family
- Jim McCormack, Oldham Rugby Football League player; father of Steve
- Steve McCormack, Widnes Vikings Super League and Scotland international representative coach; son of Jim
McCracken family
- Ken McCracken, New Zealand international player and father of Jarrod
- Jarrod McCracken (born 1970), New Zealand international; Canterbury-Bankstown Bulldogs, Parramatta Eels and Wests Tigers player; and son of Ken
McCaffery family
- Ken McCaffery, Australian international and North Sydney NSWRL player; father of Paul
- Paul McCaffery, North Sydney NSWRL player; son of Ken
- David McCaffery, North Sydney NSWRL player; son of Ken
- Michael McCaffery, North Sydney NSWRL player; son of Ken
McGregor family
- Dick McGregor, All Black international
- Dougie McGregor, All Black and Kiwis international
- John McGregor, brother of Dougie, played for Auckland
- Eric McGregor, brother of Dougie and John, played for Auckland
- Ron McGregor, Kiwis international, NZRL Chairman and President and IRLB Secretary
McGuinness brothers
- Ken McGuinness (born 1975), New South Wales Origin representative, Western Suburbs/Wests Tigers/North Queensland NRL player
- Kevin McGuinness (born 1976), Western Suburbs/Wests Tigers/Manly Warringah NRL player and Salford SL player
1st McKinnon family
- Harry McKinnon, North Sydney NSWRFL player, coach and administrator; brother of Don, Sr. and father of Doug and Max and Don, Jr
- Don McKinnon, Sr., North Sydney NSWRFL player; brother of Harry and uncle of Doug, Max and Don, Jr.
- Doug McKinnon, North Sydney NSWRFL player; son of Harry, nephew of Don, Sr. and brother of Max and Don Jr
- Max McKinnon, North Sydney NSWRFL player; son of Harry nephew of Don, Sr. and brother of Doug and Don, Jr.
- Don McKinnon (born 1955), Australian international and North Sydney/Manly Warringah NSRWFL player; Son of Harry, nephew of Don, Sr. and brother of Doug and Max
2nd McKinnon family
- Ross McKinnon, Australian international and NSWRFL player; grandfather of Wade
- Wade McKinnon (born 1981), NRL player and grandson of Ross
McRitchie family
- Doug McRitchie, Australian international, New South Wales interstate, and St. George NSWRFL player; brother of Bill
- Bill McRitchie, St. George NSWRFL player; brother of Doug
- Alan McRitchie, St. George NSWRFL player, son of Bill
- Trent Flood, Ipswich jets Queensland cup; grandson of Doug McRitchie
Mellars family
- Peter Mellars, New Zealand international and father of Vince
- Vince Mellars, NRL and Super League professional, son of Peter
Messenger brothers
- Dally Messenger (1889–1959), Australian international and Eastern Suburbs NSWRFL player
- Wally Messenger (1891–1961), Australian international and Eastern Suburbs NSWRFL player
Millard family
- Shane Millard, father of Ryan & Daryl
- Ryan Millard, brother of Daryl, Fijian international
- Daryl Millard, brother of Ryan, Fijian international
Mills family
- 'Big Jim' Mills, Great Britain and Wales international, and Widnes RFL player; father of David
- David Mills, Wales international and Widnes Super League player; son of Jim
Mincham family
- William Mincham, Auckland representative, and international referee, father of Ted, grandfather of Bob
- Ted Mincham, New Zealand international 1935–6
- Bob Mincham, New Zealand international 1966–8; son of Ted
Minichiello brothers
- Anthony Minichiello (born 1980), Australian and Italian international, New South Wales representative and Sydney Roosters NRL player
- Mark Minichiello (born 1982), Italian international, Sydney Roosters, South Sydney and Gold Coast Titans NRL player
Minto family
- Matt Minto, Newcastle Knights player; nephew of Scott
- Scott Minto, Brisbane Broncos and North Queensland Cowboys player; uncle of Matt
Mitchell brothers (1)
- Alf Mitchell, New Zealand international
- George Mitchell, New Zealand international
Mitchell brothers (2)
- Latrell Mitchell (born 1997) South Sydney Rabbitohs NRL player
- Shaquai Mitchell (born 1996) South Sydney Rabbitohs NRL player
Moliner family
- Jacques Moliner (born 1967), France international and Lezignan, Catalan, Penrith & Pamiers XIII player, father of Cyril
- Cyril Moliner, St Gaudens Bears player
Molo family
- Anthony Milford (born 1994), Samoa international & Canberra, Brisbane, Newcastle Knights & Dolphins player; cousin of both Michael & Francis
- Francis Molo (born 1994), Cook Islands & Samoa international & Brisbane, North Queensland Cowboys & St George Illawarra player; brother of Michael & cousin of Anthony
- Michael Molo (born 1997), St George Illawarra player; brother of Francis & cousin of Anthony
Monaghan brothers
- Michael Monaghan (born 1980), Canberra Raiders and Manly NRL player, Warrington Wolves Super League player
- Joel Monaghan (born 1982), Australian international, Canberra Raiders NRL player and Warrington Wolves Super League player
Morley brothers
- Adrian Morley (born 1977), GB & England, Leeds Rhinos, Sydney Roosters, Warrington Wolves & Salford; brother of Chris
- Chris Morley (born 1973), St Helens, Warrington Wolves, Salford, Sheffield Eagles, Oldham RLFC, Halifax RLFC & Swinton; brother of Adrian
Morris family
- Steve Morris (born 1957) Australian international, New South Wales representative, and St. George/Eastern Suburbs NSWRFL player; father of twins Brett and Josh.
- Brett Morris (born 1986) Australian international, New South Wales representative, and St. George Illawarra/Canterbury-Bankstown/Sydney NRL player
- Josh Morris (born 1986) Australian international, New South Wales representative, and St. George Illawarra/Canterbury-Bankstown/Cronulla-Sutherland/Sydney NRL player
Mortimer family
- Mortimer brothers
- Steve Mortimer (born 1956), Australian international, New South Wales representative and Canterbury-Bankstown NSWRL player; brother of Peter, Chris and Glen, and uncle of Daniel
- Peter Mortimer (born 1957), New South Wales representative and Canterbury-Bankstown NSWRL player; brother of Steve, Chris and Glen, and father of Daniel
- Chris Mortimer (born 1958), Australian international, New South Wales representative and Canterbury-Bankstown NSWRL player; brother of Steve, Peter and Glen, and uncle of Daniel
- Glen Mortimer, Cronulla-Sutherland NSWRL player; brother of Steve, Peter and Chris, and uncle of Daniel
- Daniel Mortimer (born 1989), Sydney Roosters NRL player; son of Peter, nephew of Steve, Chris and Glen.
Mosby family
- Hagiga Mosby, (born 2000), Brisbane Broncos player, niece of Gideon
- Gideon Gela-Mosby, (born 1996), Nth Queensland Cowboys player, uncle of Hagiga
Moses brothers
- Dai Moses – forward in the 1940s, 1950s and 1960s for Wales and at club level for Salford and Swinton.
- Glyn Moses – full back in the 1940s and 1950s for Great Britain and at club level for Salford and St. Helens
Mountford brothers
- Cecil Mountford (1919–2009), International representative and Wigan RFL player
- Bill Mountford, New Zealand representative player
- Ken Mountford, New Zealand representative player
Mueller brothers
- Blake Mueller – Newcastle NRL player
- Brock Mueller – Newcastle NRL player
Mullane family
- Mick Mullane Sr., New South Wales representative and Newtown Jets player; father of Mick Jr and Greg
- Greg Mullane, Canterbury and Cronulla player; Brother of Mick Jr
- Mick Mullane Jr., Cronulla player; Brother of Greg and father of Jye
- Jye Mullane, Cronulla and Manly player; Son of Mick Jr
- Bill Mullane, South Sydney player; Cousin of Mick Sr and Johnny Raper
Mullen family
- Jarrod Mullen, New South Wales representative and Newcastle Knights player; son of Steve
- Steve Mullen, Canterbury and Western Suburbs player; father of Jarrod
Mullins family
- Bill Mullins, New South Wales representative and Eastern Suburbs Roosters NSWRFL player; brother of Russell and Terry, and father of Brett
- Russell Mullins, Western Suburbs & Penrith NSWRFL player; brother of Bill and Terry, and uncle of Brett
- Terry Mullins, Western Suburbs NSWRFL player; brother of Bill and Russell, and uncle of Brett
- Brett Mullins (born 1972), Australian international, New South Wales representative and Canberra Raiders and Sydney Roosters NRL player; son of Bill and nephew of Russell and Terry
- Jack Hetherington (born 1996), Penrith Panthers, Canterbury Bulldogs & Newcastle Knights NRL player, grandson of Bill
- James Schiller, (born 2001), Canberra Raiders & Newcastle Knights NRL player, grandson of Bill
Mundine family
- Mickey Mundine, Aboriginal Australian team representative player; uncle of Anthony [9]
- Anthony Mundine (born 1975), Boxer, New South Wales State of Origin and St. George Illawarra NRL player; cousin of Beau
- Beau Mundine (born 1980), South Sydney NRL player; uncle of Anthony
- Tony Mundine (born 1951), boxer and Father of Anthony
- Wes Patten (born 1974), Balmain, Gold Coast, South Sydney and St George Illawarra NRL player; cousin of Anthony, Amos and Robbie
- Robbie Simpson Rugby league player with St. George, and cousin of Anthony, Robbie and Wes
- Rod Silva (born 1967), Eastern Suburbs and Canterbury Bulldogs player; Uncle of all of the above
- Buddy Gordon (born 1987), South Sydney, Canterbury and Penrith NRL player; Cousin of all of the above
- Amos Roberts, uncle of Anthony
- James Roberts, cousin of Anthony
- Tyran Smith, brother-in-law of Anthony
Myler family
- Frank Myler, Great Britain international, Widnes and St Helens RFL player, and Widnes RFL coach
- John Myler, Widnes RFL player; brother of Tony and father of Stephen
- Tony Myler, Great Britain international, Widnes RFL and Balmain NSWRL player, and Widnes RFL coach; uncle of Stephen
- Colin Myler, Super League administrator [10]
- Stephen Myler (born 1984), St Helens, Widnes Vikings and Salford City Reds Super League player; nephew of Tony
- Vinny Myler Salford and Bradford Bulls Super League player; nephew of Tony
- Richard Myler (born 1990), Widnes Vikings, Salford City Reds and Warrington Wolves Super League player - not a relation to the above. Is a relation to Widnes and Great Britain 2nd row Doug Laughton;