Fisher, who starts her new role on Friday, had worked at Talk PR since 2005, joining initially as a board director. At Talk, she worked across a number of sectors including beauty and grooming, food and beverage, fashion, finance, property and publishing.
Until now, Citizen UK MD responsibilities have been undertaken on a temporary basis by EMEA/APAC managing director Mark Cater, who was tasked with recruiting a permanent boss of the UK business.
The agency announced the appointment of new CEO Jim Joseph in the summer.
Cater said: "Helena brings a delicious mix of UK and global brand experience. Our growing portfolio of PR and influencer-marketing-led client brands will flourish under Helena’s leadership and I am looking forward to working together to expand our presence across the wider region."
According to PRWeek’s UK Top 150 Consultancies table, Citizen Relations' UK revenues were static at around £2m in 2016, employing 29 people in London.