Previously the Government advised only against travel to mainland Spain following a surge of coronavirus cases in the European country.
The announcement caused confusion among many Brits who had just travelled to or made plans to travel to Spain.
The new advice could affect Brits with plans to travel to the Balearic Islands which includes popular destinations such as Majorca, Ibiza and Tenerife.
An FCO spokesperson said: “We have considered the overall situation for British nationals travelling to and from the Balearic and Canary Islands, including the impact of the requirement to self-isolate on return to the UK, and concluded that we should advise British nationals against all non-essential travel to the whole of Spain.”
It comes after Downing Street warned “no travel is risk-free” after a coronavirus quarantine requirement for people arriving in the UK from Spain was reintroduced.
The Prime Minister’s official spokesman said decisions on border measures and travel advice “can be changed rapidly if necessary to help stop the spread of the disease”.
He said: “Unfortunately no travel is risk-free during this pandemic and disruption is possible and so anyone travelling abroad should be aware that our travel advice and exemption list is under constant review as we monitor the international situation.”
The Spanish Government had said it was in talks with the UK about excluding the Balearic and Canary Islands from its quarantine measures.
But Health Minister Lord Bethell said: “Within individual countries there is no way for us to control intra-country transport, it is therefore very difficult and challenging to have a regional exemption list, and that is why we’ve not been able to give exemptions to the Balearics.”