The former bank official, who was previously the club’s vice-chairman, succeeds Robert Cupples, who stepped down last month after 14 years in the top position.
John, a lifelong supporter of the club, has been an active board member since the year 2000 and has served as Vice-Chairman since October 2012.
Speaking after his appointment, John said: “I am honoured to be asked to be Chairman of Ballymena United Football Club and I am already looking forward to the challenges that the incoming season will bring.
“In the longer term my aims for the Club are twofold; success on the field and financial stability off it.”
Don Stirling will now take the post of Vice-Chairman vacated by John Taggart, and will also remain Football Secretary.
Don is widely recognised in local football circles as one of the country’s most skilled administrators and was recently presented with the BT Sport Merit Award at the Northern Ireland Football Writers’ Assocation Awards ceremony.