As a senior at Parkway South High School in St. Louis, Missouri, Ellison had three sacks and 47 tackles. He was ranked one of the top defensive lineman in the Midwest, won All-State honors, and was an All-Metro choice. Ellison also was a standout basketball player and received all-conference honors his senior year. He owns his high school shot put record and competed at the state track meet his junior and senior years. Parkway South High School retired Ellison's jersey in 2006.
Ellison attended Coffeyville Community College in Coffeyville, Kansas for two seasons, where he redshirted in 2000. As a freshman in 2001, Ellison started 9 of 10 games, recording 57 tackles and five sacks. Inducted into the Coffeyville Hall of Fame in 2016.
After community college, Ellison attended the University of Missouri, where as a sophomore in 2002 he played in 12 games, finishing with 39 tackles and two forced fumbles at defensive end. In 2003, Ellison earned third-team All-Big 12 Conference honors after recording 72 tackles, four sacks, and two forced fumbles. As a senior in 2004, Ellison played in 11 games, finishing with 60 tackles and 2.5 sacks, earning first-team All-Big 12 honors.
Professional career
Carolina Panthers
Ellison was drafted by the Carolina Panthers in the third round of the 2005 NFL Draft. He was waived by Carolina during final cuts on September 3, 2005, and re-signed to their practice squad two days later. On September 14, 2005, he was promoted to the 53-man roster, but was waived again on September 24, 2005. He returned to the practice squad on September 27, 2005, and was elevated to the active roster again on October 31, 2005, where he spent the remainder of the season as an inactive. He was waived by the Panthers on September 2, 2006.
Houston Texans
The Houston Texans claimed Ellison off waivers on September 3, 2006, but waived him on September 7, 2006, before the start of the regular season.
Baltimore Ravens
Ellison was signed to the practice squad of the Baltimore Ravens on September 12, 2006, and was elevated to the 53-man roster on December 4, 2006. He was inactive for three games before being placed on injured reserve with a shoulder injury on December 30, 2006. He was waived by the Ravens on September 1, 2007, and re-signed to their practice squad the next day.
The San Francisco 49ers signed Ellison to their 53-man roster off the Ravens' practice squad on September 5, 2007. He was inactive for the entire 2007 season and was waived by the 49ers on August 30, 2008, and re-signed to the 49ers' practice squad the next day.
Jacksonville Jaguars
The Jacksonville Jaguars signed Ellison off the 49ers' practice squad on December 10, 2008, but he was inactive for the final three games of the regular season. Ellison made his NFL debut as a reserve in Week 1 of the 2009 season. He went on to play in 15 games for the Jaguars in 2009, starting nine at defensive tackle. He finished the season with 28 tackles and one and a half sack. He was waived by the Jaguars on September 4, 2010.
Kansas City Chiefs
The Kansas City Chiefs signed Ellison on October 20, 2010. He was inactive for one game before being waived on October 27, 2010.
New England Patriots
Ellison was signed by the New England Patriots on January 4, 2011, prior to their first playoff game. He was waived on January 8, 2011.
