|UFC 84: Ill Will|
|Promotion||Ultimate Fighting Championship|
|Date||May 24, 2008|
|Venue||MGM Grand Garden Arena|
|City||Paradise, Nevada, USA|
|Attendance||14,773 (13,448 paid)|
The card featured the return of Sean Sherk, who was suspended and stripped of his UFC lightweight title after he tested positive for steroids at UFC 73. He faced B.J. Penn, who had since won the vacated title against Joe Stevenson at UFC 80. This event also marked the last appearance of Tito Ortiz in the UFC for well over a year, as he was at the end of his contract and due to his feud with Dana White was not expected to re-sign at the time.
This event also marked the UFC debut of future UFC Interim Heavyweight Champion Shane Carwin.
This event was awarded Sherdog's 2008 Event of the Year.
Preliminary card 
- Carwin defeated Wellisch via KO (punch) at 0:44 of round 1. This bout aired on the PPV broadcast following the Gouveia vs. Reljic fight.
- Kim defeated Tan via KO (elbows) at 0:25 of round 3.
- Yoshida defeated Koppenhaver via submission (anaconda choke) at 0:56 of round 1. This bout aired on the PPV broadcast following the Penn vs. Sherk fight.
- Clementi defeated Etim via unanimous decision (29–28, 29–28, 29–28).
- Sokoudjou defeated Nakamura via TKO (leg injury) at 5:00 of round 1. This bout aired last on the PPV broadcast following the Koppenhaver vs. Yoshida fight.
- Palhares defeated Salaverry via submission (armbar) at 2:36 of round 1. This bout aired on the PPV broadcast following the Silva vs. Jardine fight.
Main card 
- Silva defeated Mendes via submission (punches) at 2:24 of round 1.
- Reljic defeated Gouveia via TKO (punches) at 3:15 of round 2.
- Machida defeated Ortiz via unanimous decision (30–27, 30–27, 30–27).
- Silva defeated Jardine via KO (punches) at 0:36 of round 1.
- Penn defeated Sherk via TKO (flying knee and punches) at 5:00 of round 3 to retain the UFC Lightweight Championship.
Bonus awards 
At the end of this event, the UFC awarded $75,000 to each of the fighters who received one of these three awards.
- Fight of the Night: Wilson Gouveia vs. Goran Reljic
- Knockout of the Night: Wanderlei Silva
- Submission of the Night: Rousimar Palhares
Fighter payroll 
B.J. Penn ($250,000) def. Sean Sherk ($35,000)
Wanderlei Silva ($150,000) def. Keith Jardine ($10,000)
Lyoto Machida ($100,000) def. Tito Ortiz ($210,000)
Goran Reljic ($6,000) def. Wilson Gouveia ($18,000)
Sokoudjou ($80,000) def. Kazuhiro Nakamura ($20,000)
Thiago Silva ($50,000) def. Antonio Mendes ($4,000)
Rousimar Palhares ($10,000) def. Ivan Salaverry ($20,000)
Yoshiyuki Yoshida ($12,000) def. Jon Koppenhaver ($8,000)
Rich Clementi ($40,000) def. Terry Etim ($10,000)
Dong Hyun Kim ($40,000) def. Jason Tan ($3,000)
Shane Carwin ($12,000) def. Christian Wellisch ($10,000)
This does not include fighter bonuses
Total: $1,098,000 
- MMAWeekly.com staff (2008-05-31). "UFC 84 OFFICIAL GATE AND ATTENDANCE TOTALS". MMAWeekly.com. Retrieved 2008-05-31.
- "UFC 84 Fight Card". ufc.com. February 26, 2008. Retrieved 2008-02-26.
- "Silva, Palhares, Reljic and Gouveia secure $75K UFC 84 bonuses". MMAJunkie.com. May 25, 2008. Retrieved 2008-05-25.
- UFC 84 fighters' salaries: payroll tops a million bucks | MMAjunkie.com