Just 13 per cent of voters said it was in their top three issues when deciding who to vote for with the issue rating 9th overall out of 13 issues put to 927 respondents.
According to the poll conducted by JWS Research, same-sex marriage made the top three list of just 4pc of Coalition voters. It was not a top three issue for 72pc of Greens and 85pc of Labor voters.
ACL Managing Director Lyle Shelton said the poll confirmed what MPs have been saying for the past three years in Parliament.
"During the many same-sex marriage debates in the last Parliament MPs consistently said same-sex marriage was simply not a priority for people in their electorates. Despite Kevin Rudd and Labor elevating the issue to front and centre of the election campaign, this sentiment has not changed," Mr Shelton said.
"Same-sex marriage had an extremely high media profile during the election and yet it still failed to register as an important issue for the overwhelming majority of voters.
"The fact that Kevin Rudd made it an election issue and lost so convincingly, and these figures of just 4pc of Coalition voters supporting same sex marriage, mean Tony Abbott must maintain support for man-woman marriage as a party policy," Mr Shelton said.
The poll also found support for changing the Marriage Act had slipped dramatically. Most polls had shown around 63pc support for same-sex marriage but the JWS poll found just 45pc of people thought the Marriage Act should be changed.
Thirty-eight per cent of people were opposed to law change with 17pc undecided.
"Despite years of high-profile campaigning and the demonising of those speaking up for man-woman marriage, support for changing the Marriage Act appears to be slipping," Mr Shelton said.