The Tasmanian parliament has become the first in Australia to formally support same-sex marriage.
Giddings said the vote was a great day for the state.
"Tasmania has come a long way since 1997 when we rectified the terrible situation of having homosexual relationships considered illegal in this state," she said. "We've come a long way to show we are in fact a tolerant and compassionate community."
Australian Marriage Equality national convener Alex Greenwich said people nationwide followed the debate.
"What they heard today was a message of hope. They heard a message of hope coming out of the Tasmanian Parliament that one day gay and lesbian Australians will be treated equally by the law and by the Marriage Act," he said. "This gives us the momentum and the encouragement to go on and keep fighting."
Tasmanian Greens Leader Nick McKim said Tasmania was sending a clear message to Canberra, and specifically federal Labor, who will debate same-sex marriage at its national conference in December.
"Its time for the federal government to change our nation's laws and provide for marriage equality for all Australians, regardless of gender, regardless of sexuality," he was quoted as saying in the Sydney Morning Herald.
"The Tasmanian parliament has given thousands of same-sex couples around Australia – and their families and friends – hope that change is coming."
Although Prime Minister and Labor leader Julia Gillard has expressed her support for retaining the current definition of the Marriage Act which does not recognise same-sex marriages, motions of support for marriage equality have been passed by her party’s Queensland, Tasmania, West Australia, South Australia, Victoria, ACT and Northern Territory branches.