From the Universityh of North Texas, Markeith Knowlton signed with the BC Lions a sa free agent for 2006. Knowlton played mainly on special teams in his rookie season, but did have one pass interception that he returned 67 yards for a touchdown. Knowlton took a more regular turn on defence at defensive half in his second season with BC in 2007, recording 42 defensive tackles.
Knowlton was traded to Hamilton for the 2008 season and the Tiger-Cats converted him to an outside linebacker where he blossomed into an All-Star. Knowlton won East All-Stars at linebacker in 2008, 2009 and 2010 as well as CFL All-Stars in 2009 and 2010. In 2009 and 2010, Knowlton was also the Hamilton nominee for most outstanding defensive player in the CFL.
| Year | Team | GP | T | ST | Total | TFL | Yds | KD | Sacks | Yds |
|---|---|---|---|---|---|---|---|---|---|---|
| 2006 | BC | 15 | 8 | 14 | 22 | 0 | 0 | 3 | 0 | |
| 2007 | BC | 17 | 42 | 3 | 45 | 0 | 4 | 5 | 2 | |
| 2008 | HAM | 18 | 95 | 0 | 95 | 5 | 7 | 3 | 2 | |
| 2009 | HAM | 18 | 94 | 1 | 95 | 2 | 6 | 3 | 1 | |
| 2010 | HAM | 18 | 71 | 0 | 71 | 3 | 4 | 3 | 3 | |
| 2011 | HAM | 18 | 64 | 0 | 64 | 3 | 4 | 4 | 3 | |
| 2012 | HAM | 43 | 0 | 43 | 0 | 0 | 1 | 1 |
| Year | Team | Int | Yds | Avg | TDInt | Long | FR | Yds | Avg | TD | Long | FF |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2006 | BC | 1 | 67 | 67 | 1 | 67 | 1 | 0 | 0 | 0 | 0 | 0 |
| 2007 | BC | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 |
| 2008 | HAM | 4 | 121 | 30.3 | 1 | 48 | 0 | 0 | 0 | 0 | 0 | 4 |
| 2009 | HAM | 4 | 40 | 10 | 1 | 35 | 4 | 4 | 1 | 1 | 4 | 4 |
| 2010 | HAM | 3 | 7 | 2.3 | 0 | 5 | 6 | 8 | 1.3 | 1 | 4 | |
| 2011 | HAM | 1 | 1 | 1 | 0 | 1 | 2 | 0 | 0 | 0 | 0 | 1 |
| 2012 | HAM | 0 | 0 | 0 | 0 | 0 | 1 | 5 | 5 | 0 | 5 |
