"She had no idea," the MYX VJ said in his caption when he posted an Instagram video of the surprise.
"She's here for school, and has never been away this long from home."
Hannah, who is a popular YouTuber, cried tears of joy when she saw Donny pop out behind a car.
The third child of Anthony Pangilinan and Maricel Laxa is studying a one-year Music and Film course in Sydney.
Donny once expressed to PEP.ph (Philippine Entertainment Portal) how proud he is of his sister.
Back in March 2018, he said, "Magaling kumanta yun, magaling din sumayaw, and magaling din umarte.
"Nasa kanya na lahat so I'm proud of Hannah. Kahit ano kaya niyang gawin."
Among the five Laxa-Pangilinan children, only he and Hannah have shown interest in showbiz.
But for now, Hannah chose to focus on her studies.
As a big brother, Donny admitted that he isn't "too strict."
The ABS-CBN host-actor added, "Basta lahat ng ginagawa niya, very supportive ako."