Reid, alongside Belgian Joachim Gerard, won 6-3 3-6 1-0 (10-3) against fellow Briton Alfie Hewett and Gus Fernandez.
The Scot, 25, won Wimbledon last year alongside Hewett, after previously winning the US and French Open (twice).
"It was a last-minute decision to play with Jo but one that has paid off," Reid said.
"I don't think any one of us played our best tennis today but we upped our level when it mattered."
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There could be more British success in Melbourne after Andy Lapthorne reached the quad singles final.
Lapthorne, 26, will meet Australia's Dylan Alcott, who beat him in the 2016 Rio Paralympics final, on Rod Laver Arena on Saturday after semi-final opponent Heath Davidson pulled out through injury.
Lapthorne is aiming for a double after teaming up with American David Wagner on Thursday to win his fifth Australian Open quad doubles title.
Britain's Gordon Reid completed a career Grand Slam in the wheelchair men's doubles by winning the Australian Open in a final-set tie-break.