Barcelona AVE to Madrid

Since you are already at the airport. Look into booking a discount airline to Madrid.

Check Skyscanner.com for flights. I see some good fares for your travel date. Be careful about extra charges for seat selection, luggage, etc. And be even more careful about the airport being used (though all the non-stops seem to be BCN). I have no idea how much time you need to allow to make a separately ticketed connection. Your inbound flight could be late, or you could get hung up in Immigration.

If you wish to take the train (it's not a particularly pretty route much of the way), check Renfe for schedules. AVE (fast train) departures are frequent, generally once or twice per hour. Second class is fine, any AVE will get you there fast. As with flying, the question is how much of a time buffer do you need. The usual recommendation is to wait until arrival to buy your rail tickets, but fares will continue to increase as you get closer to your travel date. It looks as if the 2nd-class fares top out at 128 euros.

Here's information on the train between the city and El Prat Airport. The Aerobus works fine, too, but it drops you at Pl. Catalunya rather than at Sants Stations, which is where you would pick up the AVE to Madrid.

Frank makes a great point. Yet if you prefer to travel by train...

• Train from Terminal 2 in the airport straight to Sants. Note Sants it's NOT terminus for this line as it goes on to Estació de França, east of the city, but you'll recognise Sants immediately because it's the biggest underground hub in the city, with more than 16 tracks. Important: you DON'T need to go to the centre, both the airport and Sants station are to the west.
• If you land in Terminal 1, there's a continuous free service of transfer between terminals by a (green) bus to get to Terminal 2. They depart every 5'.
• The train from Terminal 2 departs every 30' (06' and 36' if I'm not mistaken, check it out.. btw, the name of the station at the airport is "Aeroport", Catalan for airport) and the journey to Sants takes 20'. Assuming you've already purchased your AVE ticket, you need to go up to the main hall and simply head to the Information desk, located in the middle of the station. They'll tell you which track you need for AVE, this way you don't waste any time. There's a security point to access the AVE trains where you're luggage is x-rayed, much like at the airport.
• No best value.... there's only one sort of tickets for this short journey from the airport to Sants so you can board any carriage.
• As per time for Customs/immigration, etc upon your landing at the airport, that's difficult to estimate as it can wildly vary. This is one of the top10 busiest airports in Europe and while the infrastructure is in line with the number of passengers using the premises, sometimes there are bottlenecks for a myriad of reasons. Thus it's difficult to estimate as it depends on too many factors -take it from someone that uses this airport very often. Having said that, it shouldn't take you more than say 45' all together -but again, take this estimate with a pinch (or better a full spoon!) of salt.

I highly recommend taking the AVE. It is fast and affordable. If you book it enough in advance, you can easily get it to around $54 euros. Since you are already in Spain, there is no immigration but there is baggage clearance. You can not take ANY knives in your luggage or any other sharp objects. Renfe does scan baggage. No need to pay for the first class ticket, the train is really nice. When You arrive in Madrid, your ticket will give you a ride on the Circanias for no additional charge. You will then take the Circanias to the Plaza Del Sol station. Be mindful that the metro stations in Madrid vary in whether they have an escalator, so don't bring heavy luggage!!! Some stations have them, or they may have them to one platform but not others - it is a pain! Depending on which exit you take at Plaza Del Sol, there is one that does have a lift, but the other does not.

Look online about traveling from the airport to the train station. I am sure it is easy.

I would arrive at the train station at least 20 minutes ahead of boarding.

I would take the train over another flight, but you can also check Vueling, they are having a sale right now - purchase two tickets with a discount. Hurry on that, it won't last long!

Thank you all for your comments/suggestions! How much time should we allocate for Customs/Immigration, baggage pickup, transfer to domestic terminal and security check? We arrive at 10am and depart at 2pm.

Based on Franks recommendation and confirmed by others, we have decided to take a Vueling Optima (50lb suitcase) flight from the Barcelona airport to Madrid. A Vueling one-way flight is only $50 versus the AVE train is over $100!

Thanks again for all your feedback!

I am not sure when you are referring to customs and immigrations. You said you are arriving at 10 and leaving at 2, Basically, just stay at the airport. If you arrive into Barcelona on an international flight, you will have to collect your bags, go through customs and immigrations, and then check in for your Vueling flight to Madrid as that is a local flight. You will have plenty of time.

We used the AVE from Barcelona to Madrid last month. That trip was a highlight of our visit to Spain. The station is well marked and the ride is very impressive....smooth and efficient. We booked through Petrabax, which was also an easy experience.