Michael Jameson will take over the role of director of children’s services on Monday.
Mr Jameson, who was executive director at Oldham Council, had started at the authority as director of children's services in 2009.
Since then Oldham children's services moved from ‘adequate’ to ‘excellent’ and the authority made progress across children’s and adults services.
In recent weeks he has been working part-time in Bradford alongside Mrs Tunstall to ensure a smooth transition.
Mrs Tunstall said: “He has a strong team around him and is very keen to be working in Bradford.
“The message I’d leave for him is he is so fortunate to have the job of director of children’s services in a district like Bradford. There is a vibrancy and excitement to the city.
“It is a privileged role to be in to look after our children and young people. I’d tell him to keep pushing hard for improvements and never be complacent.”