The Spanish economy grew by 0.6% in the first three months of the year, compared to the revised 0.7% in the prior quarter, the National Statistics Institute said on Tuesday.
The year-on-year GDP growth was 2.8%, compared to 3.3% in the previous quarter.
Although the economy's pace of growth is therefore easing, Spain is still outperforming many of its European neighbours.
In the coming months, consumption is expected to remain robust thanks to rising wages, high savings, and immigration.
Domestic demand contributed 0.4 points to quarter-on-quarter growth, while external demand contributed 0.2 points.
Domestic demand contributed 3.2 points to year-on-year GDP growth, while external demand contributed -0.4 points.
The figures cover the period from January to March, meaning the effects of US President Donald Trump's trade war have not yet been taken into account.
Spain also released inflation data on Tuesday, which showed that the Consumer Price Index (CPI) came to 0.6% month-on-month in April, compared to a reading of 0.1% in March.
Annual CPI came to 2.2%, down from 2.3% in March, with the drop driven by falling electricity and fuel prices.
