According to the WHO, tap water is safe for consumption for 99% of the country.
Tap water is safe to drink in Portugal.
According to the CDC tap water is generally safe for consumption.
According to the Numbeo water drinkability and accessibility index, tap water has a score of 80.35 / 100 (100 being best).
Numbeo considers this score to be "Very high"
Portugal is a member of the European Union which ensures tap water safety across its countries.
1 adult could save about 453$ per year in Portugal by drinking tap water instead of buying bottled water.
๐ณ Drinking tap water would also help with reducing your plastic footprint and improve environmental pollution.
Like in most countries, water quality and accessibility differs from location to location, therefore it's the best to check the information available on that place.