| Mazarmatic | Tropical Seeds Company | | 80/20 | View variety |
| Mazarsaurus | Desert King Mountain High Seed Co. | | 50/50 | View variety |
| Maze OG | The Bank Genetics | | 80/20 | View variety |
| MB15 (Cantucci lineage, Umami Seed Co) | Unknown | | Unavailable | View variety |
| MB232 | Second Generation Genetics | | 40/60 | View variety |
| Mc Early | Kannabia Seeds | | 50/50 | View variety |
| MC Hammer Auto | Viking Gardens | | 60/40 | View variety |
| Mc Kushers | Conscious Genetics | | 60/40 | View variety |
| MCF - Mouth Coating Fuel | Riot Seeds | | 60/40 | View variety |
| McFarlane | Doc's Dank Seeds | | 50/50 | View variety |
| McFly | Unknown | | 60/40 | View variety |
| McFritter | Elev8 Seeds | | 60/40 | View variety |
| McPayton | Elev8 Seeds | | 50/50 | View variety |
| McRuntz | Elev8 Seeds | | 60/40 | View variety |
| McVerde | Elev8 Seeds | | 70/30 | View variety |
| Mean Mug | Freeborn Selections | | 50/50 | View variety |
| Meao Thai | Cannabiogen | | 0/100 | View variety |
| Meat Breath #12 S1 | ThugPug Genetics | | 50/50 | View variety |
| Meat Grinder | The Grateful Seeds | | 60/40 | View variety |
| Meat Madness | ThugPug Genetics | | 50/50 | View variety |