This comes days after the broadcast giant reworked its advertising rates.
Hsu brings over 16 years of experience in both Taiwan and China, where she managed international clients across several different categories.
Ong was previously with Viacom International Media Networks where she was responsible for corporate and brand communications for Asia Pacific.
She starts her new role today and will manage a team of approximately 30 to 40 individuals.
He was Chanel's creative director for over three decades.
The agency also has 14 shortlisted entries in PR Awards 2019.