Football Federation Australia are hoping the later start will help define soccer as the only summer football code as it does battle with the more popular Australian Rules and rugby league and union operations in a congested sports market.
Although a crowd of more than 50,000 watched the Brisbane Roar beat the Central Coast Mariners to win the A-League title in March, attendances overall were down on previous years.
As well as reducing the number of midweek matches, the FFA has also promised a bigger and smarter marketing outlay for next season.
Twice champions Sydney FC, once the glamour team of the A-League whose crowds dropped below 10,000 last season, welcomed the moves.
"We think the move to an October start date is the right move for the A-League," acting CEO Stefan Kamasz said.
"There are plenty of local derby matches and fixtures where strong rivals face each other throughout the opening rounds too, so as a league we can have a strong start to the season and build really good momentum from there."
The first round of matches will take place on Oct. 8 with the final matches of the regular season taking place on March 25 before the "finals series" to decide the champions.