UFC 98: Evans vs. Machida is an upcoming mixed martial arts event to be held by the Ultimate Fighting Championship (UFC) on May 23, 2009 in Las Vegas, Nevada.

A title unification match between the UFC Interim Heavyweight Champion Frank Mir and UFC Heavyweight Champion Brock Lesnar was originally slated to be the main event, but was postponed to a later date due to a knee injury to Mir.

By way of replacement, Quinton Jackson, former UFC Light Heavyweight champion, was to fight the undefeated current champion Rashad Evans but had to undergo arthroscopic surgery to repair ligament damage in his jaw that he received in a previous training camp. Instead, Evans will headline the card against undefeated contender Lyoto Machida.Jackson will then face the winner of Evans vs. Machida for the title on a date that is yet to be determined.

The card also features the long anticipated grudge match between The Ultimate Fighter 6 coaches Matt Hughes and Matt Serra.

Due to injury, Josh Koscheck will not be able to participate on this card. Brock Larson stepped in as the new opponent for Chris Wilson.

James Irvin was set to make his Middleweight debut against Drew McFedries, but will not be able to fight due to a knee injury.Xavier Foupa-Pokam stepped in to fight McFedries.

Yushin Okami was set to fight Dan Miller on the main card but was injured and is off the card, Okami suffered a torn ligament. Early reports suggested Ed Herman would replace Okami, however Chael Sonnen has stepped in to take the bout.

Houston Alexander was scheduled to fight Andre Gusmao, but has been forced to pull out due to a broken hand. Krzysztof Soszynski has stepped in to fight Gusmao.

Main card
Light Heavyweight Championship bout:  Rashad Evans vs.  Lyoto Machida
Welterweight bout:  Matt Hughes vs.  Matt Serra
Middleweight bout:  Drew McFedries vs.  Xavier Foupa-Pokam
Middleweight bout:  Dan Miller vs.  Chael Sonnen
Lightweight bout:  Sean Sherk vs.  Frank Edgar

Preliminary card
Welterweight bout:  Brock Larson vs.  Chris Wilson
Heavyweight bout:  Patrick Barry vs.  Tim Hague
Lightweight bout:  Phillipe Nover vs.  Kyle Bradley
Light Heavyweight bout:  Krzysztof Soszynski vs.  Andre Gusmao
Welterweight bout:  Yoshiyuki Yoshida vs.  Brandon Wolff
Lightweight bout:  Dave Kaplan vs.  George Roop