Port staff told CBC News that more public transit will cut down on congestion and make it easier to move goods.
An official announcement on the Port's participation in the Yes side is expected in March.
But in confirming the support now to CBC News, the Yes side adds a powerful partner to its already extensive list of supporters, which includes labour unions, business groups, cycling advocates and medical health officers.
Ballots will be sent out starting March 16th, with voting concluding on May 29th.
The referendum seeks to approve a 0.5 per cent increase to the provincial sales tax in Metro Vancouver to pay for a ten-year transit plan with a price tag of $8 billion.
The increased sales-tax would provide $250 million a year in revenue.
The Yes side could use a boost as a recent survey shows that currently the No side has more support due to a lack of faith in TransLink.