As general manager, corporate affairs, Taggart will report to UK and Ireland CEO Ed Williams and join the UK executive operations team.
He will be responsible for growing the firm's integrated client work, overseeing its 30-strong Ireland operation, and leading the firm's corporate affairs practices - made up of its corporate reputation and public affairs practices, and Smithfield, the financial division acquired in 2015. Together, these three practices have well over 100 staff.
Taggart had previously worked at Bell Pottinger, joining in 2012 as a director and rising to partner. At the start of this year he was MD of newly launched Engage, a new practice bringing together its corporate, brand, digital and content teams. Clients included South African Tourism, HSBC, Amazon, Huawei and Qatar Airways.
Prior to Bell Pottinger, he worked for Betfair both in the UK and in his native Australia.
Edelman's corporate affairs units have seen several changes recently, making a number of hires to its public affairs team including former Downing Street aide Craig Woodhouse, after a new leadership team of Boris Johnson adviser Will Walden and Stronger In's Lucy Thomas was installed at the end of last year.
The corporate reputation team is now led by Rachel Bower. Formerly deputy MD of the business under Nick Barron, his departure to MHP has resulted in Bower's promotion.
Taggart said: "It's a big thrill to be joining a company that I've admired for a long time and it's particularly exciting to be joining at a time when the business has made significant investment into its corporate affairs practices.
"We share very similar views on how we need to shape the offer and I'm now looking forward to working with the outstanding individual teams to create a more holistic and powerful corporate affairs proposition for Edelman and its clients."