No, Tengen Uzui does not die in Demon Slayer: Kimetsu no Yaiba. Although he suffers severe injuries and poisoning during the Entertainment District Arc, he ultimately survives the battle against the Upper Rank Six demons, Gyutaro and Daki.
What Happens to Tengen Uzui?
Gravely Injured: Tengen is poisoned by Gyutaro and loses an arm and an eye during the intense fight.
Survives the Poison: With assistance from his allies, especially Nezuko—who uses her demon blood to burn away the poison—Tengen is saved from certain death.
Retires from Demon Slaying: Due to his injuries, Tengen chooses to retire from the Demon Slayer Corps but remains alive and later appears in a supportive role.
Clarifying Misconceptions
Some fan discussions and speculative posts have mistakenly suggested that Tengen dies or is resurrected. However, canon sources from both the Demon Slayer anime and manga confirm that he survives and retires peacefully with his wives.
Summary: Tengen Uzui is critically injured but does not die. He survives the battle and lives on after retiring from active duty.