Costa, who is from Summerside, is just the second UNB player to be named the conference's top libero since the award was established in 1999-20000. Kyle Blanchard was the first to win the award in the 2010-11 season.
Costa led the conference this season with 2.06 digs per game.
"Andrew had to assume this new role in his last year with us, making the switch from setter to libero a seamless one," said UNB head coach Dan McMorran. "He has had a very solid season, leading the AUS in digs/sets, but also providing energy and leadership in our backcourt."
The Varsity Reds recently captured the AUS championship.