Mackenzie Lynne Dern Santos is an American professional mixed martial artist and Brazilian Jiu-Jitsu practitioner.
She is a former world No. 1 ranked IBJJF competitor, currently ranked 6th among the female divisions.
As of April 12, 2022, she is #4 in the UFC women's strawweight rankings and #12 in the UFC women's pound for pound rankings.
Dern was born in Arizona, the daughter of Wellington "Megaton" Dias, a highly decorated grappling competitor himself.