Landry transferred to Purdue University, located in West Lafayette, Indiana for his junior year in 2004–05, where he led the conference with 18.2 ppg and led the Boilers with 7.1 rpg. He shot 61.8 percent from the field and averaged 30.3 mpg while playing under head coach Gene Keady. His best game of the season came against Michigan State when he scored a season-high 31 points while shooting 11-of-12 from the floor. On the season, he scored in double figures 22 times and recorded six double-doubles. He was named second-team All Big Ten by conference coaches and media despite missing the season's final three games due to an ACL injury in his right knee.