The MPs have spoken of discrimination, disbelief and determination to change marriage laws to allow same-sex couples to wed.
The gay Liberal senator behind the same-sex marriage bill never believed his relationship would have equal recognition.
Dean Smith was embraced by politicians from all sides after Thursday's speech, the first in the parliamentary debate on legislation to allow same-sex marriage.
"I never believed the day would come when my relationship would be judged by my country to be as meaningful and valued as any other. The Australian people have proven me wrong," Senator Smith told parliament as he fought back tears.
Australians returned a resounding yes vote to the government's marriage equality survey, with 61.6 per cent of people supporting a law change.
"It wasn't just a vote of acceptance, it was that deep loving embrace of a big family," Senator Smith said.
Senator Smith's bill was introduced to the upper house on Wednesday with cross-party support.
The alternative legislation, which would have allowed businesses to refuse to provide services for gay weddings on religious grounds, was abandoned.
He said amendments which wound back freedoms for gay and lesbian Australians would be "strenuously opposed".
Labor Senate Leader Penny Wong said she first felt the power of prejudice when she moved to Australia from Malaysia as an eight-year-old.
"It is from this experience that I am driven to remove discrimination and embed equality," Senator Wong said.
She finished her speech with a heartfelt tribute to her partner, Sophie, and their two daughters.
"Hannah and Alexandra, I work for and fight for the world I want for you," Senator Wong said.
Greens Senator Janet Rice told parliament she had been discriminated against after her partner Penny became a woman, 17 years after they married.
"We went from being the perfect family in the eyes of others to being weird and we started being discriminated against," Senator Rice said.
"You don't know the pain of having to let go of your partner's hand because you're not sure the reaction it might get from people around you."
Labor's Louise Pratt choked up as she told the Senate she wanted to marry her partner, Bec.
"I know we share the feelings of other same-sex couples who look forward to the focus turning from a massive public debate about our lives and our identities and turning towards each other, for the love we share for each other and for our children," Senator Pratt said.
Liberal senators Simon Birmingham and Linda Reynolds said they would oppose amendments which would curtail rights for same-sex couples.