COVID testing prior to entering Portugal?

Technically yes. There are many threads about this. Because while Portugal does require a negative test to enter, many people are finding that the test is never checked. But Portugal does require it

I am not sure of the rules of Portugal entry. However, I don't think vaccinations and boosters are the main concern of most countries, except that it limits the volatile hospitalization needs. Vaccinations and boosters will assist you in fighting off the virus, but vaccinated or not, you can be infected and a carrier. That is the need of testing. Covid vaccines and boosters do not stop you from becoming infected.

as Jessica says above, Technically yes. the airline won't ask for it - but Portugal does - and in the last month, they have NOT been checking at the airport (although they did when I flew early april)

Someone posted that the Lisbon airport is randomly checking only 25% of non-EU and reciprocal nation passengers for proof of a negative test. That’s why so many are posting that documentation of a negative test was not asked for. I suspect that those who ARE being asked to show proof are not posting their experience. So reading the other thread/posts, it may seem that nobody is asked upon arrival at Lisbon. The US is not a reciprocal nation for a vax card so the negative test is required for entry. I don’t like the 1 in 4 odds so I’m going to get tested before departure and hope it is negative.

I see Portugal's Council of Ministers has just extended the country's "situation of alert" until June 30, so all measures currently in place will presumably remain so until then. Darn! I was crossing my fingers that the test requirement for non-EU visitors would be dropped by the time we depart on June 26. Definitely rethinking this ..... My husband has Covid right now and it would be impossible for him to travel feeling as he does.