Madrid to Sevilla travel options

I would take the train to Sevilla and a taxi to Atocha train station. See options, prices, and time in this link: https://madrid-international-airport.com/transportation/airport-to-atocha-train-station/
It's about 30 minutes to Atocha by taxi or train, but I could not venture a guess as to how long to get out of the airport--it's quite large. Are you checking luggage? I think 30 minutes or so is a good rough estimate.
I would not prebook the train, just download the Renfe app and buy tickets en route.

The best way to handle it would be a flight from Madrid since you are already at the airport. Otherwise you need to get to the train in town, etc.. And that is a hassle. Give yourself a four, maybe five hour window and buy trip insurance for the flight to Sevilla. For other readers a better option would have been to book a flight to Sevilla from the US and return from Madrid under a ticket option often called Open-Jaws or Multi-city ticketing. Probably would have saved money.

Frank, You really think hanging out in Barajas airport for 4-5 hours to wait for a connection is less of a hassle than heading straight to the train station in a cab and hopping on a high speed train (where you can comfortably nap en route)?
I hate the travel part of travel myself, but I don't get that--just sayin'!

For timing purposes, I passed through Barajas in the 4th arriving about 7:30am, and it literally took an hour from the time I got off the plane until I cleared immigration. The line reminded me of Heathrow before the e-gates.

If it was my trip, when buying airline tickets I’d get a flight all the way to Sevilla. If you’ve already purchased the ticket to Madrid then go with the train option.

Martin, your question about "can you exchange your train ticket for an earlier one if you arrive earlier" is a good one. As I read the various train ticket options, it seems that you would get some of the ticket price back, not all of it.

Can anyone here clarify?

I agree that flying to Seville on the same ticket as the transatlantic flight would be simplest and safest from a schedule standpoint. However, when folks are heading to Seville and buy airline tickets to Madrid instead, it's usually because of price. On my most recent trip to Spain, flying into Seville would have cost me an extra $500 with no change in my return ticket. My solution, planned from the beginning, was to spend the first night in Madrid and pre-puchase onward transportation for the next day. But I'm retired and had plenty of time to spend my jetlagged arrival day in Madrid.

I've never needed to get a train ticket refunded, so I'm not going to try to answer that question. The official policy will be on the Renfe website, and it depends on the type of ticket you choose.

There's a complication here that no one has mentioned: It's quite common for Spanish express trains to sell out before departure time. I see that often when I look up schedules--several fast trains in a row listed as "full". Therefore, the usual advice not to buy arrival-day long-distance train tickets until you're on the ground at the destination is risky in Spain.

That potentially major issue aside: There's a train station at the Madrid airport. I had no trouble finding it in 2016 even in a zombified state. Those folks will sell you a ticket (or perhaps it's a pair of tickets) to Seville. They know how long it will take to get the train from the airport to Atocha Station. I'd ask about the transfer time, because I find Atocha a bit confusing. I'd want to have a bit of a time buffer. They will also put your luggage through a scanner, which may take a few minutes.

What you must not do is end up in the line for the staffed ticket counters at Atocha. They are disastrously understaffed or inefficient or both. I was in that line for 3 hours, and it is a chronic situation going back years. The ticket-vending machines worked with my US credit card--I was just too sleep-deprived to figure out how to buy a senior ticket--and it has been quite some time since I read a complaint about credit card issues for Americans. I think some machines take currency as well, but I've never used that in a train-ticket machine. In any case, buying the onward ticket at the airport train station (if you don't want to buy one in advance) avoids any potential ticketing issue at Atocha.

Since you have already purchased your airline tickets, I would recommend that you take the subway or a taxi to Atocha Station and purchase your ticket when you arrive at the station. Nothing like having your flight to Madrid delayed or cancelled or there a long line for passport control. Most people in Europe seem to purchase their train tickets when they arrive at the station.

Thanks for info and tips so far. At end of trip we will be back in Madrid for a few days before flying home.
We are not going until February, so still time to research further. Thanks.

40 minutes is my average from plane to curb at MAD’s T4 complex. Though once immigration itself was a 40 minute line. (Iberia floods T4 with early arrivals from the americas. I understand it’s faster at T1.)

The Cercanias train is free with purchase of a long-distance Renfe ticket. Easy choice from T4.

I’d buy the train ticket with at least three hours gap from landing time. A first class, or “Preferente” ticket will be more flexible if, by chance, you can catch an earlier train, and will include lounge access if you have time to kill at the station.

Just took the AVE fast speed train from Seville to Madrid. Very easy and fast only 3 hours.

We took the AVE high speed train from Seville to Madrid. It took 3 hours and it was a beautiful ride! I recommend paying a little extra and riding in first class. The tickets were cheap online around 30.00. Omio was the site.