Bird, a co-founder of the Bartle Bogle Hegarty spin-off Soul Advertising, will now take charge of the agency’s creative department.
Kean was promoted to joint executive creative director alongside Tom Ewart in 2008 following the latter’s arrival from Shop. Ewart departed in June last year to help form the start-up agency The Corner, leaving Kean in sole charge.
It is not known if Kean, who quit the agency this week, has a job to go to.
Bird, having spent the majority of his career at BBH, where he became the head of art aged 27, joined Ogilvy in 2007, two years after Soul was acquired by Nitro.
At Ogilvy, he was responsible for accounts including Europcar, Expedia, Castrol and Kraft. He joins Publicis later this year.
In November, Publicis hired JWT’s head of planning, Tony Quinn. He is also expected to join later this year.
Karen Buchanan, the Publicis London chief executive, said: "Andy is a real talent and has an eye for creating and inspiring great work and inspiring those around him. His entrepreneurial background with big agency experience make him ideal for ensuring that we deliver world-class creativity for all our clients."
The appointments are the first major hirings made by Buchanan since joining from The Red Brick Road in 2011.