Scotland's Jane Ross scored the equaliser for the host in the 59th minute at Falkirk Stadium on Thursday, firing from 12 yards to cancel out Laura Alleway's first-half opener for Australia.
Alleway struck in the 26th minute, prodding the ball home off a scrappy scramble in the box after a corner.
It came minutes after keeper Brianna Davey saved a penalty kick by Scotland's Kim Little, given after Stephanie Catley was called for a handball in the box.
The match marked the 81st and final game for veteran Matildas midfielder McCallum, rounding off her decade-long international career.
Late substitute Samantha Kerr returned to the field for the first time since a knee injury sidelined the Perth Glory attacker in December.
The match follows the Matildas' 2-1 loss to Austria on Tuesday and wraps up their European tour.
The squad will return home to complete preparation for the World Cup campaign in Canada, with it's first group match against USA on 8 June.
Backing up from a match against Austria just 36 hours earlier combined with a tumultuous 18 hours of travel from Villach to Falkirk, Matildas coach Alen Stajcic was full of praise for his team’s performance.
“We played a lot of good football today and really dominated the first 45 minutes like we haven’t done for a long time so we should have really been three or four goals up at half time,” Stajcic said.
“It came back to bite us in the end when Scotland created a couple of chances in the second half and scored from one of them, so it’s disappointing that we didn’t win but the performance was excellent and a testament to the players’ hard work over the last six weeks.
“The effort today was superb, the execution on the field was brilliant and it was just that little bit in the penalty box that let us down but if we can improve that facet of the game we’re certainly capable of beating anyone.
“I don’t think I’ve seen a Matildas team dominate an opponent like we did today. We should have really buried them because we had a host of chances, but it just shows how far we’ve come as a team.”
Stajcic also paid a final tribute to McCallum, who bows out of the game after 81 senior international appearances and 11 goals for her country.
“Collette is a brilliant person on and off the field and in my opinion one of the top few Matildas of all time,” the coach said.
“She is a tremendous footballer so we’re all extremely happy for her and proud of her career and we wish her all the best for the future.”
