Chris Sinnott, currently deputy to the shared chief executive Gary Hall, was the unanimous choice of both authorities after an extensive selection process.
The £145,000-a-year job will become vacant when Mr Hall stands down on December 31.
The former Chorley chief executive has held the joint post since it was created in November 2020 following the departure of Heather McManus at South Ribble.
At the time Mr Hall accepted the job on a fixed term basis until the end of 2022.
Both councils, which share a number of services and executive roles, started the search for a successor on February 28 and completed the selection process in seven weeks.
Mr Sinnott emerged as the preferred candidate after a round of interview panels including a stakeholder panel which featured Supt Gary Crowe from Lancashire Police, Diane Gradwell, the chief executive of Lancashire West Citizens Advice and Claire Russell the principal and CEO of Runshaw College.
He then faced a panel of staff from both authorities, before having one-to-one interviews with the leaders of both Chorley and South Ribble Councils, Coun Alistair Bradley and Coun Paul Foster.
There followed a technical interview with another council chief executive - Bolton's Tony Oakman.
And finally he appeared before the Shared Services Appointment Panel, where members agreed "unanimously" he should be recommended to both councils for formal appointment.
"Feedback at all stages of the selection process was very positive, and the view of internal and external stakeholders was that the candidate was suitable for the role," says a report to go before both full council meetings - Chorley on Tuesday April 19 and South Ribble on Wednesday April 20.
Mr Sinnott's £145,000 salary - the same as that currently paid to Gary Hall - will be divided equally between the two authorities.
Mr Sinnott, who holds a degree in politics, a post graduate diploma in law and a masters in public management, previously worked at Blackpool Council as policy manager before joining Chorley Council.
He was director of policy and governance before becoming Chorley's deputy chief executive in December 2019.