It was originally enacted in November 2015 following a suicide bomb attack on a bus.
This though came after 38 people, including 30 British holidaymakers, were killed by a gunman in the tourist resort of Sousse.
The extension was confirmed by Tunisian president Beji Caid Essebsi on Wednesday (November 7).
A statement from the president’s office said the move related to the “security situation” in the country.
The Foreign and Commonwealth Office (FCO) updated its guidance on Wednesday.
“A state of emergency is in effect in Tunisia, imposed after a suicide attack on a police bus on November 24, 2015. It’s been extended a number of times, most recently on November 5, 2018, by one month.
“Since the terrorist attack in Sousse in June 2015, which targeted tourists, the UK government has been working closely with the Tunisian authorities to investigate the attack and the wider threat from terrorist groups. The Tunisian government has improved protective security in major cities and tourist resorts.
“Terrorists are still very likely to try to carry out attacks in Tunisia, including against UK and Western interests. Security forces remain on a high state of alert in Tunis and other places. You should be vigilant at all times.”
In June though, the FCO softened its travel advice for Tunisia, reflecting changes made by the Tunisian authorities and the general security situation in the country.
Wahida Jaiet, director of the Tunisia National Tourist Office, said the change was a “huge boost to confidence” in Tunisia, adding: “2018 is the year to rebuild faith and trust in Tunisia.”
The country has bounced back this year with Thomas Cook and Tui returning after the Sousse attack. British visitor numbers are also expected to eclipse estimates for the year, Jaiet revealed at WTM London this week.
Flight capacity will double next year too, with focus on regional departures.