The 2017 Hertfordshire County Council election took place on 4 May 2017 as part of the 2017 local elections in the United Kingdom. All 78 councillors were elected from electoral divisions which returned one county councillor each by first-past-the-post voting for a four-year term of office.
Boundary changes to the electoral divisions took effect at this election after a review of the county by the Local Government Boundary Commission for England increasing the number of seats on the council from 77 to 78.