| No | Entrant | Races | Active Years |
|---|
| 581 | M. Burn (Non-champ only) | 1 |
1954 |
| 582 | M. Pete Wales (Indy only) | 2 |
1950, 1955 |
| 583 | M.A. Walker (Indy only) | 3 |
1950–1951, 1953 |
| 584 | Madom Formula 1 Team (Non-champ only) | 1 |
1979 |
| 585 | Maki Engineering | 9 |
1974–1976 |
| 586 | Manor Marussia F1 Team | 19 |
2015 |
| 587 | Manor Racing MRT | 21 |
2016 |
| 588 | Mapfre-Williams | 1 |
1976 |
| 589 | Marcel Balsa | 1 |
1952 |
| 590 | March Engineering | 44 |
1970, 1974–1977 |
| 591 | March F1 | 16 |
1992 |
| 592 | March Grand Prix Team | 16 |
1981–1982 |
| 593 | March Racing | 15 |
1976 |
| 594 | March Racing Team | 3 |
1973 |
| 595 | Maria-Teresa de Filippis | 3 |
1958 |
| 596 | Mario Deliotti Racing | 1 |
1978 |
| 597 | Marlboro BRM | 27 |
1972–1973 |
| 598 | Marlboro McLaren | 16 |
1993 |
| 599 | Marlboro McLaren International | 109 |
1981–1987 |
| 600 | Marlboro McLaren Mercedes | 33 |
1995–1996 |
| 601 | Marlboro McLaren Peugeot | 16 |
1994 |
| 602 | Marlboro Team Alfa Romeo | 60 |
1980–1983 |
| 603 | Marlboro Team McLaren | 81 |
1976–1980 |
| 604 | Marlboro Team Texaco | 32 |
1974–1975 |
| 605 | Marquis de Portago (Non-champ only) | 5 |
1955 |
| 606 | Marshall Wingfield (Non-champ only) | 7 |
1976 |
| 607 | Martin Birrane (Non-champ only) | 1 |
1977 |
| 608 | Martini Racing | 50 |
1975–1977 |
| 609 | Martini Racing Team | 13 |
1972–1973 |
| 610 | Martini Racing Team Lotus | 17 |
1979 |
| 611 | Marussia F1 Team | 55 |
2012–2014 |
| 612 | Marussia Virgin Racing | 19 |
2011 |
| 613 | Maserati Race Cars (Indy only) | 1 |
1951 |
| 614 | Mastercard Lola F1 Team | 1 |
1997 |
| 615 | Matra International | 23 |
1968–1969 |
| 616 | Matra Sports | 14 |
1967–1968 |
| 617 | Maurice Trintignant | 5 |
1964 |
| 618 | McLaren F1 Team | 161 |
2018–2025 |
| 619 | McLaren Honda | 39 |
2015, 2017 |
| 620 | McLaren Honda Formula 1 Team | 21 |
2016 |
| 621 | McLaren Mercedes | 19 |
2014 |
| 622 | McLaren's of Broxburn (Non-champ only) | 3 |
1977 |
| 623 | Meiritsu Racing Team | 1 |
1977 |
| 624 | Mel B. Wiggers (Indy only) | 2 |
1952, 1954 |
| 625 | Melchester Racing | 20 |
1976–1979 |
| 626 | Memphis International Team Surtees | 1 |
1974 |
| 627 | Mercedes AMG Petronas F1 Team | 237 |
2012–2017, 2020–2025 |
| 628 | Mercedes AMG Petronas Motorsport | 42 |
2018–2019 |
| 629 | Mercedes GP Petronas F1 Team | 38 |
2010–2011 |
| 630 | Mervyn Kearon (Non-champ only) | 1 |
1956 |
| 631 | Merz Engineering Inc (Indy only) | 1 |
1955 |
| 632 | Michael Young (Non-champ only) | 5 |
1954–1955 |
| 633 | Midland F1 Racing | 15 |
2006 |
| 634 | Mike Anthony (Non-champ only) | 2 |
1955 |
| 635 | Mike Christie (Non-champ only) | 1 |
1953 |
| 636 | Mike Clarke (Non-champ only) | 1 |
1956 |
| 637 | Mike Fisher | 2 |
1967 |
| 638 | Mike Harris | 1 |
1962 |
| 639 | Miklos Sperling (Indy only) | 1 |
1954 |
| 640 | Mild Seven Benetton Ford | 16 |
1994 |
| 641 | Mild Seven Benetton Playlife | 49 |
1998–2000 |
| 642 | Mild Seven Benetton Renault | 67 |
1995–1997, 2001 |
| 643 | Mild Seven Renault F1 Team | 88 |
2002–2006 |
| 644 | Milt Marion (Indy only) | 1 |
1950 |
| 645 | Minardi Cosworth | 18 |
2004 |
| 646 | Minardi F1 Team | 19 |
2005 |
| 647 | Minardi Scuderia Italia | 33 |
1994–1995 |
| 648 | Minardi Team | 145 |
1985–1987, 1989, 1991–1993, 1996–1997 |
| 649 | Modena Team SpA | 16 |
1991 |
| 650 | Momo Corporation | 1 |
1961 |
| 651 | MoneyGram Haas F1 Team | 58 |
2023–2025 |
| 652 | Moneytron Onyx Formula One | 24 |
1989–1990 |
| 653 | Monte Carlo Auto Sport | 1 |
1959 |
| 654 | Monteverdi Onyx Formula One | 2 |
1990 |
| 655 | Mopar Ultramar Racing Team (Non-champ only) | 1 |
1979 |
| 656 | Motor Presse Verlag | 1 |
1952 |
| 657 | Motor Racers Inc (Indy only) | 1 |
1954 |
| 658 | Motor Racing Developments | 109 |
1969–1974, 1989–1990 |
| 659 | Motor Racing Developments Ltd | 75 |
1985–1987, 1991–1992 |
| 660 | MRD International | 16 |
1984 |
| 661 | MTV Simtek Ford | 21 |
1994–1995 |
| 662 | Murrell Belanger (Indy only) | 7 |
1950–1956 |
| 663 | Myson Racing (Non-champ only) | 5 |
1976 |
