Mr Gandy has previously held roles at Carillion, Lend Lease and Brookfield Multiplex.
He will lead Kier’s construction business across London, south and west England, and Wales.
The role reports into Kier’s building UK executive director Peter Young.
Mr Young said: “I’m delighted to welcome Paul to Kier. His extensive industry experience will complement our existing management team and his broad understanding of the southern UK market will be invaluable as we work towards our Vision 2020.”
Mr Gandy added: “This is an exciting time for me to be joining Kier. Vision 2020 is an ambitious target and I’m eager to contribute to this and continue to grow Kier’s existing presence across the south of the country.”