Stevenson will replace Iain Mackay who is retiring. HSBC CEO John Flint described Stevenson as a "strategic thinker" and "accomplished expert" in his field.
"He brings a wealth of international experience and will be a welcome addition to the senior management team," Flint said in a statement.
Flint thanked Mackay, 56, for his 11 years of service, eight of which were in his current role. Specific retirement and appointment dates will be confirmed in due course, HSBC added.
The appointment of 52-year-old Stevenson completes a new top team at HSBC, with CEO Flint and Chairman Mark Tucker also taking up their posts in the past year.
Since joining RBS in 2014 and alongside RBS CEO and fellow New Zealander Ross McEwan, Stevenson has led efforts to turn around the bank's fortunes following its 45.5 billion pound bailout in 2008.
RBS has spent the last decade shedding trillions of dollars in assets and dealing with the legal and regulatory hangover from an unfettered pre-2008 global expansion.
Since the start of the year, the bank has resolved a number of key legacy issues, with Stevenson playing a key role.
It announced his surprise departure in May, without specifying what his next job would be.
"For the past four years Ewen has worked tirelessly with me and my executive team to make RBS a much simpler, safer and more customer focused business and resolve a number of major legacy challenges," McEwan said at the time.
British newspapers speculated following announcement of his departure that Stevenson would move to HSBC, but the CFO declined to give anything away.
"I am delighted to be joining HSBC. I look forward to working with the board, John and his executive team," he said in a statement on Monday.
Prior to RBS, Stevenson spent 25 years at Credit Suisse, with his last role being co-head of the Europe, Middle East and Africa investment banking division and co-head of its global financial institutions group.
(Reporting by Emma Rumney; Ediitng by Silvia Aloisi/Keith Weir)