There are 4 seasons and 96 episodes of My Name is Earl (TV Series) from 2005 to 2009.
So that, My Name is Earl (TV series) have 4 seasons :
1. Season 1: (2005–06)
2. Season 2: (2006–07)
3. Season 3: (2007–08)
4. Season 4: (2008–09)
See more details here : Tvguide