The third season of the American television series Tough as Nails premiered on CBS on October 6, 2021, and concluded on December 8, 2021. The season was won by jill-of-all-trades Lia Mort, with diesel mechanic Dequincey "Quincey" Walker finishing second, and heavy equipment operator Jerome Kupuka'a placing third.
Dequincey "Quincey" Walker appeared on the fourth season during the automotive service challenges of the fourth episode. Lamar Edwin Hanger appeared on the fourth season during the construction challenges of the seventh episode. Lia Mort appeared in the fifth season during the apple-loading challenge in the fifth episode.
On April 14, 2021, CBS announced that Tough as Nails was renewed for a third and a fourth season. On June 7, Phil Keoghan revealed on the show's social media that filming had begun at Marine Corps Base Camp Pendleton. The contestants also competed at Mount Baldy, the United States Coast Guard Base in San Pedro, and the Irwindale Speedway. On July 12, 2021, it was announced that the season would premiere on October 6, 2021.
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