Tourists visiting Spain rose to 630,657 in April from a virtual zero in the same month a year ago, statistics department INE said on Tuesday.
However, it was still 91 per cent lower than in April 2019, INE reported.
Travellers from Germany were the most to visit Spain, representing 23 per cent of the tourists in April.
This was followed by France as many citizens visited Spain to take a break from early curfews and restrictions back home.
Foreign tourists spent a total 671 million euros in April, 90 per cent less than in the same month in 2019, and a total of 1.9 billion euros in the first four months of 2021, 83 per cent less than last year, INE said.
It comes as a travel expert has said that more green list countries are expected to be added to the list this Thursday.
According to PC Agency's Paul Charles, both the Canary and the Balearic Islands in Spain could be added and open from June 7 - the next date for the easing of travel restrictions.
Mr Charles told the Sun: "The next green list review is due by Thursday 3rd June with implementation from Monday 7th June.
"Several criteria determine a country’s colour but two are key: 14-day infection rate and ability to do regular genomic sequencing, to check for variants.”
The Balearic Islands, which contains Majorca and Ibiza, have 35 cases per 100,000, compared to the UK's 44.9.
Meanwhile, The Canaries are currently at 80.8 per 100,000, making it one of the lowest in Europe.
Malta is also likely to be added with high vaccine uptake and just 25 cases per 100,000.
Spain reopened to British tourists on Monday, May 24, with no testing requirements for arrivals, but the country remains on the UK’s amber list meaning returning travellers must quarantine.
Business minister Anne-Marie Trevelyan said scientists still think there is “too great a risk” in travelling to amber list countries for non-urgent reasons such as holidays.
Spain expects to be added to the UK green list at the next Government review, the country’s tourism minister has said.