The 2009 LSU Tigers baseball team represented Louisiana State University in the NCAA Division I baseball season of 2009. This was the first year for the team in the new Alex Box Stadium. The 2009 team was coached by Paul Mainieri who was in his third season at LSU. During his first year at LSU, Mainieri's team posted a 29–26–1 record, but failed to make the SEC Tournament or the NCAA Tournament. The team improved during his second year posting a 49–19–1 record, while claiming the SEC Western Division Title, SEC Tournament Championship, and earned the No. 7 National Seed for the 2008 NCAA Tournament. They advanced to the 2008 College World Series.