He played college football at Oregon State, recording career totals of 104 receptions for 1,109 yards and 10 touchdowns.

Hamlett signed with the Jacksonville Jaguars after going undrafted in the 2015 NFL draft, but was waived before the start of the 2015 season.

Hamlett was also a preseason member of the Dallas Cowboys in 2017 but suffered an injury and was released before the start of the 2017 season.

He later played for the Arizona Hotshots of the Alliance of American Football in 2019 and the Seattle Dragons of the XFL in 2020.

Hamlett was a three-year letterman in football at Meadowdale High School in Lynnwood, Washington as a tight end.

[8][2][4] Meadowdale High finished with an 11–1 record his senior year; winning the first 11 games before losing in the Class 3A state quarterfinals.

[5] He earned second-team All-WesCo South honors his junior year in 2008–09 as Meadowdale won a share of the WesCo South title, won the 3A District 1 title and also finished sixth in the Class 3A state tournament.

[13][14][15] He was team co-captain his senior year and garnered first-team All-WesCo South accolades after averaging 19 points and 10 rebounds.

[5][16][17] In the 2010 Class 3A state boys basketball tournament, Hamlett averaged 24 points and 10 rebounds per game and earned first-team All-Tournament honors as Meadowdale High finished in fifth place.

[20][32] When Hamlett committed to Oregon State in February, the team offered him a grayshirt, which he accepted.

[33][34] In March, it was reported that Hamlett was not grayshirting as originally planned and was instead walking-on in 2010 and going on scholarship after the season.

[43][44][45][46] In July 2014, Hamlett was named to the watchlist for the John Mackey Award, which is given to the best tight end in college football.

[5] He reportedly played his senior season "at about 80 percent" due to knee pain and other issues.

[50] He was the fifth Oregon State tight end to record at least 1,000 career receiving yards.

[1] In a January 2015 story with The Herald, it was reported that Hamlett was retiring from football due to knee problems.

"[43][51] In a story with The Florida Times-Union shortly after signing with the Jacksonville Jaguars, Hamlett said, "I just took some time off because I was banged up" and that "I love the game of football, and I wanted to play.

[51] Due to his break, he did not participate in the 2015 NFL Combine or Oregon State's Pro Day.

Zierlein stated that Hamlett was "Stiff, with limited athleticism" and that he "must improve his play strength at the point of attack and make his way as a blocking tight end to have a shot".

[66] He made his NFL debut, and first career start, against the New England Patriots on October 9 and recorded one reception, a 17-yard touchdown pass from Charlie Whitehurst.

[81] In October 2019, Hamlett was selected by the Seattle Dragons during the 2020 XFL draft's open phase.