Glassie was born in Atiu, and educated at Atiu Primary School, Tereora College, then St Stephens School in Auckland.[2] He attended the University of Auckland, graduating with a bachelor of Arts, before completing a Masters in Public Policy at Massey University.[2] He had a long career as a public servant for the New Zealand Department of Labour, the Manukau City Council, and the Cook Islands Government. From 2005 – 2006 he was chief of staff in the office of the Cook Islands Prime Minister.[2]
Glassie was re-elected in the 2010 election and appointed to Cabinet as Minister of Health and Minister of Agriculture.[3][4] A Cabinet reshuffle in November 2013 saw him lose the Agriculture portfolio to Kiriau Turepu and take over as Minister of Internal Affairs, the Ombudsman, and Parliamentary Services.[5]
He was re-elected at the 2014 election.[6] A further Cabinet reshuffle in March 2015 saw him yield the Internal Affairs and Ombudsman portfolios to Albert Nicholas and become Minister of Justice.[7] During this term Glassie launched a mental health strategy[8] and a health workforce plan.[9]
He lost his seat at the 2018 election to Te-Hani Brown.[10][11] Following his election loss Glassie founded the Cook Islands United Party with former MP Teariki Heather.[12] He subsequently contested the 2019 March Tengatangi-Areora-Ngatiarua by-election, sparked by the defection of Te-Hani Brown from the Democratic Party, as a Democratic Party candidate, but was unsuccessful.[13] When Brown resigned again to avoid an unfavourable election petition ruling, he was too ill to contest a second by-election.[14]
Glassie had four sons and lived with his wife in Rarotonga. He died on Rarotonga on 4 September 2020 of cancer.[1]