Gordon Tempest-Hay, who headed Teneo in the UK and Blue Rubicon, will succeed Tony Langham at Lansons on January 1.
Langham, co-founder of the London-based firm, will become executive chairman, focusing on client work. Fellow co-founder Clare Parsons will shift from non-executive chair to non-executive director.
Tempest-Hay, who just wrapped up his non-compete after exiting Teneo two years ago, said it's time to get back to the fray and make up for lost time.
"You know in your gut when you've found the right place and have an opportunity to build something truly special. Lansons is that place," he said.
Langham said he and Parsons felt it was time to put a succession plan in place and called Tempest-Hay "our number one target."
Lansons, which acquired New York-based Intermarket in 2019, has 100 people serving clients such as JPMorgan Private Bank, Cayman Islands, Manulife, Fidelity International, Royal Mint and Invesco.