The 2003 Jacksonville Jaguars season was the franchise's 9th season in the National Football League and the 1st under head coach Jack Del Rio. The Jaguars failed to improve upon their 6–10 regular season record in 2002 and failed to make the playoffs for the fourth season in a row. An 0–8 record in road games eliminated any chance of postseason play. Oddly, despite being in existence since 1995, this season marked the first time that the Jaguars played the San Diego Chargers. This is due to old NFL scheduling formulas in place prior to 2002; the Jaguars had played the Chargers’ division rivals the Kansas City Chiefs four times; the Denver Broncos three times and the Oakland Raiders twice (though not since 1997). Week 3 was Mark Brunell's last game as a Jaguar, as he was benched forcing rookie quarterback Byron Leftwich to take his spot for the rest of the season. Brunell left the team at the end of the season. Jacksonville defeated New Orleans 20–19 in the week 16 game despite the River City Relay, a play that has gone down in NFL lore.

Offseason

Acquisitions

During free agency, the Jaguars signed former Philadelphia Eagles defensive end Hugh Douglas and former Indianapolis Colts linebacker Mike Peterson.

NFL draft

Undrafted free agents

Staff

Final roster

Preseason

Regular season

Schedule

Note: Intra-division opponents are in bold text.

Game summaries

Week 1: at Carolina Panthers

Week 2: vs. Buffalo Bills

Week 3: at Indianapolis Colts

After being down 3–0 at halftime, the Colts scored 17 third quarter points followed by six points in the fourth quarter to beat Jacksonville 23-13 and improve to 3–0. A standout moment from the game occurred when Colts' rookie DB Mike Doss caused a fumble by Jaguars' RB Fred Taylor. Doss reportedly quipped, "Hey, Fred, you forgot something." In retaliation, Taylor told reporters ahead of their next encounter, "I'm going to bust his (butt). I'm going to punish him."

Week 4: at Houston Texans

Week 5: vs. San Diego Chargers

Week 6: vs. Miami Dolphins

Week 8: vs. Tennessee Titans

Week 9: at Baltimore Ravens

Week 10: vs. Indianapolis Colts

By the start of the fourth quarter, the Jaguars rallied with two touchdowns to take the lead. On the next possession, Peyton Manning connected with Marcus Pollard, who raced 70 yards to set up a go–ahead field goal. The Jaguars then moved deep into Colts' territory, but a fumbled field goal snap by punter/holder Mark Royals thwarted their efforts. After the Colts went three–and–out and a strong punt return set Jacksonville up at the Indianapolis 31–yard line, Fred Taylor made a 32–yard run, evading Mike Doss as he fell, to score a touchdown and put the Jaguars ahead with just a minute remaining. Manning's attempt to respond ended in an interception, sealing the Jaguars' first–ever victory over the Colts in a surprising upset. After the game, Doss remarked, "I guess you'd have to say he got the final word today." Taylor expressed that his frustration arose from Doss forcing his head to the ground after he recovered the fumble, expressing "I felt he truly disrespected me,"

Week 11: at Tennessee Titans

Week 12: at New York Jets

Week 13: vs. Tampa Bay Buccaneers

Week 14: vs. Houston Texans

Week 15: at New England Patriots

Week 16: vs. New Orleans Saints

Week 17: at Atlanta Falcons

Standings

Division

Conference