He was joined on a recent trip to the ground by Deputy Mayor Cllr Andrew Wilson and Cllr Bobby Hadden.
The addition of the stand and turnstiles will bring the ground up Intermediate League status.
Mid and East Antrim Council in partnership with Greenisland Football Club have been working together to deliver the new stand.
Through working in partnership, the club have been able to secure £45,000 of external funding and along with a contribution from the club, Council are contributing £35,000 to deliver the £90,000 spectator stand.
Mayor Johnston said: “I would like to pay tribute to Greenisland Football Club and in particular the time and commitment that the club members put into progressing this project.
“As a Council, we have been delighted to help fund a portion of this work and to enable the vision and objectives of the club to be met. Greenisland Football Club are a fantastic club and it is no surprise that they have recently been recognised from UEFA as one of the top grassroots football clubs in Europe.”
Mervyn Montgomery, Greenisland FC, said the club was indebted to council for their support.
“We are indebted to the on-going support of our External Funders and Mid & East Antrim Borough Council, to enable us to build upon the existing facilities at Greenisland and to develop further our Community Sports Programs and longer term plans for the Club.”
The new stand will further enhance the major investment Mid and East Antrim Council made in 2018 through the delivery of a new 3G facility on the back of £100,000 of funding the club secured from SportNI.
The Club and Council had also secured external funding to upgrade the grass pitches, which are owned by the Council, in 2018 at a cost of £50,000.