The move follows the departure of former Broxbourne head of comms John Entwistle to lead the PR department at the London Borough of Havering after ten years in the post.
As head of communications and customer services, Fieldhouse will oversee the council's corporate comms team, which consists of four PROs and two designers. She will also take charge of communications for the customer services department.
She joins on 31 May and will report to chief executive Michael Walker.
Her responsibilities include improving communications with residents and partner organisations through its network of town centre one-stop shops.
Last November the Audit Commission gave the council a 'good' rating in its first comprehensive assessment.
It commended the council for its strong engagement and consultation with the community, and applauded its services and financial position. However, it said Broxbourne needed to improve its information provision to the public.
At Hertsmere, Fieldhouse initiated the council's first consultation strategy, ensuring it met the requirements of the Freedom of Information Act.
She also produced its internal and external publications and launched and managed its website. Hertsmere has not started to recruit for her replacement.