UFC president Dana White confirmed the date and location at a media luncheon in Las Vegas on Monday. Las Vegas-based MMA reporter John Morgan first tweeted the news.
Velasquez (12-1) captured the UFC heavyweight title at UFC 121 on Oct. 3, 2010, by defeating then-champion Brock Lesnar by technical knockout in the first round.
He and dos Santos (16-2) first met during the UFC’s debut event on the Fox Networks on Nov. 12, 2011. Dos Santos knocked out Velasquez in just over a minute to win the title and earned Knockout of the Night.
The two faced off for a second time at UFC 155 on Dec. 29, 2012. Velasquez defeated dos Santos in a one-sided bout to reclaim the UFC heavyweight title.
Dos Santos is coming off a highlight reel knockout of Mark Hunt at UFC 160 on May 25. Velasquez successfully defended his belt against Antonio Silva in the main event of the same card.
The heavyweight title bout is the only announced match-up for the Oct. 19 card at this time, but announcements for the remaining fight card are expected in the coming weeks.