The much-loved series was cancelled earlier this year after 37 years, after UK broadcaster Channel 5 decided that it was dropping the show from its schedule.
According to TV Tonight, the soap’s finale was the top-rated show of the night in Australia, with a whopping 873,000 people across the country’s five state capital cities tuning in. Deadline said it was the programme's biggest TV audience in 13 years.
Donovan, 54, said goodbye by posting an old photo on Instagram showing him in his Neighbours days.
He also shared a montage of clips of him and Minogue as Scott and Charlene, including glimpses of their TV wedding. It was set to the pair’s song 'Especially For You', which they are set to re-release to mark the end of the series.
“Farewell!” he wrote.
Quoting a line from the Neighbours theme tune, the actor added: “That’s when good neighbours become good friends.”
Several other cast members have also paid tribute to the soap, which started in 1985.
Ryan Moloney, who starred as Toadfish since 1995, kept things light-hearted when he appeared on Good Morning Britain.
“Thank you so much to everybody that has watched over the time," he said.
“Your support has meant so much - everyone that’s watched, and everyone that hasn’t watched… I guess maybe that’s why we got fired,” he joked.
Annie Jones, who plays Jane Harris, shared a photo of several cast members all sat together watching the finale.
“We all got together to watch the final episode last night,” she said.
“A few tears, and a lot of laughs. Such a great bunch of people.”
Stefan Dennis, who starred as Paul Robinson, was on This Morning talking about the end of the soap.
He shared that Hollywood star Margot Robbie, who returned to her role of Donna for the finale, sent a special gift as the cast shot their last scenes.
"Margot sent us 37 bottles of champagne for our final wrap, after the finale scene, to open," he said.
"And we did, we popped them in the studio and celebrated.
"I just thought it was such a lovely thing she did, a bottle of champagne for each year of Neighbours."
The finale will be shown in the UK tonight (29 July), at 9pm on Channel 5.
Watch: Neighbours: Actress Delta Goodrem says finale is 'very special'