How to get from Seville to Salema, then to Lisbon?

I have never been to Salema, but there have been many posts on this forum from people who said it was a disappointment, spoiled by over-tourism. You might use the Search function here to look at some of those earlier posts.

It appears that your transportation choices are ALSA, Eva or Damas bus to Lagos then Eva bus to Salema OR bus to Faro/train to Lagos/bus to Salema. You can drill down on Rome2Rio.com to find links to the companies running those buses and check their schedules. Do not trust the fares, travel times, or frequencies displayed on the Rome2Rio website itself. I think you'll find the buses you need are rather infrequent, and it's going to be a long trip.

Spain and Portugal are not well-connected by ground transportation.

There's no rail service between Salema and Lisbon, so that will be another bus ride.

Are you sure you want to do this? I'd spend all the time in Lisbon, going to Sintra and perhaps Cascais. Or there are other spots on the Algarve that would somewhat shorten your transportation time. You'll find suggestions for alternatives to Salema in some of the earlier posts. (I admit to never having been to Salema.)

Or consider stopping off in Evora en route to Lisbon from Sevilla.

What are the goals of staying in Salema? Transportation from Seville to Salema will require 6-8 hours by bus with a change in Faro. Check Rome 2 Rio.

Our experience with a rental car involved 3 nights in Burgau and 2 nights in Faro. We had a lovely apartment in Burgau with the deck looking to the west toward the beach. There were good eating options and a lovely above the sea walk to the east and a walk on the beach to the west. A walk or bike ride could have gone to the west to Salema. We opted for car trips. Getting west or east by car is slow on the local road and fast on the toll hi way.

Faro has small scale beautiful churches with bones, the living quarters for the Bishop of the diocese, a blue interior church by car, local eateries with nice servers, a long sandy beach by car near the airport and a very busy airport.

I would suggest you skip the south of Portugal. In the future, I would have no problem staying in the area for greater than a week.

Although the cathedral in Seville is over the top. Lisbon's sites and day trips required 5 nights for us in the past. FLY Seville to Lisbon.

We are doing exactly this only the opposite direction. We will pick up a rental car when we are done with Lisbon, sightsee Algarve and drop it in Faro and then us mydaytrip.com for a private direct ride to Seville (about $200 for 4).