The bill breezed through 43 votes to 12, and the moment was met with a standing ovation in the packed public and parliamentary galleries. 

Senators from various parties hugged each other and cried following the vote, with some declaring it the proudest day in their parliamentary careers.

"This is the Senate's day," Liberal senator Dean Smith said shortly after. "This is a demonstration that working across the chamber ... does deliver not just good outcomes but fantastic outcomes."

An industry in need to help: marriage slides to an all-time low

Attorney-General George Brandis said he was "so proud of Australian democracy today, more proud than I have ever been". It was a day to "rejoice in what the Australian people achieved this year", he said.

The bill must now proceed to the House of Representatives. Prime Minister Malcolm Turnbull cancelled this week's sitting of that chamber, ostensibly to wait for the Senate to finish debating the same-sex marriage bill, which was originally expected to take until Thursday.

Labor's Senate leader Penny Wong – who is gay and fought within Labor for years to change its position on same-sex marriage – said it was a day of "great celebration for so many people across this country".

Senator Smith, the first openly gay Liberal MP, helped drive the change within the Coalition and sponsored the final bill that passed the chamber essentially unchanged on Wednesday afternoon.

"We have seen in this debate how our Parliament is meant to work," he said. "The real question out of this debate is why isn't our Parliament like this more often?"

Parliamentarians from both sides had a conscience vote on the bill, and many chose to abstain - including Employment Minister Michaelia Cash, Assistant Social Services Minister Zed Seselja and One Nation leader Pauline Hanson.

Those who voted against the change included Resources Minister Matt Canavan, International Development Minister Concetta Fierravanti-Wells and Labor senators Chris Ketter and Helen Polley.

Various amendments to the bill – including moves to allow civil celebrants to refuse to perform gay weddings – were defeated in the Senate on Tuesday and Wednesday by a combination of Labor, the Greens, some Coalition senators and some crossbenchers.

HOW THEY VOTED:

YES VOTERS

Liberals

Simon Birmingham

George Brandis

David Bushby

Mathias Cormann

Jonathon Duniam

Mitch Fifield

Ian ​Macdonald

Nigel Scullion

Anne Ruston

James Paterson

Jane Hume

Marise Payne

Linda Reynolds

Scott Ryan Dean Smith

Labor

Carol Brown

Catryna Bilyk

Doug Cameron

Kim Carr

Anthony Chisholm

Kimberley Kitching

​Sue Lines

Jenny McAllister

Malarndirri McCarthy

Claire Moore

Louise Pratt

Lisa Singh

Anne Urquhart

Murray Watt

Penny Wong

Greens

Andrew Bartlett

Richard Di Natale

Sarah Hanson-Young

Nick McKim

​Lee Rhiannon

Janet Rice

Jordon Steele-John

Rachel Siewert

Peter Whish-Wilson

Crossbench

​Stirling Griff

Rex Patrick

David Leyonhjelm

​Derryn Hinch

NO VOTERS

Labor

Chris Ketter

Helen Polley

Liberals/Nationals

Concetta Fierravanti-Wells

Eric Abetz

Slade Brockman

John Williams

Matt Canavan

Barry O'Sullivan

Crossbench

Lucy Gichuhi

Fraser Anning

Cory Bernardi

Brian Burston

DID NOT VOTE

Liberals/Nationals

Michaelia Cash (abstained)

David Fawcett (abstained)

James McGrath (abstained)

Zed Seselja (abstained)

​Arthur Sinodinos (on leave)

Bridget McKenzie (abstained)

Labor

Jacinta Collins (paired)

Sam Dastyari (attending funeral)

Pat Dodson (leave)

Don Farrell (attending funeral)

Alex Gallacher

Katy Gallagher (leave)

Gavin Marshall (overseas)

Deb O'Neill (abstain)

Glenn Sterle

Crossbench

Pauline Hanson (abstained)

Peter Georgiou (abstained)