Paris to Vienna and Salzburg

Salzburg is much closer to Munich than to Vienna; Salzburg is so close to Germany that some German rail passes include Salzburg. I think you'd do better to fly from Paris to Munich and get a train there. Rail-travel time will be about 1-1/2 to 1-3/4 hours. By comparison, the train trip from Vienna to Salzburg takes about 2-1/2 hours. There are frequent departures to Salzburg from the Munich Hauptbahnhof. I can't help you with the easiest way of getting from the airport to the Hauptbahnhof, but it's possible there's good bus service from the Munich airport straight to Salzburg. I bet someone else will see this thread soon and fill in the gaps.

I'd also recommend flying to Munich. The Sbahn leaves the airport evey 10 minutes for the Hauptbahnhof and takes about 45 minutes. No need to buy the train ticket to Salzburg in advance. Buy on the Deutche Bahn app or website once you land, or buy at the station.

Thank you both. Looks like the flight availability to Munich is better than Vienna, too.

An even better option in my opinion is to simply take the train from Paris to Salzburg. Flying to Munich won't really save you any time compared to the train and the train is much easier and more comfortable.

IN ORDER of PREFERENCE

1 Fly to Vienna early in the day and spend the day and night in Vienna and take the 2.5 hour train later train the next day. Even if for only one night Vienna is worth the stay. When will you have the opportunity to do this again. You can buy the train ticket in advance this way which might save 20 euro on the cost.

for me if a night in Vienna is first, then a night in Munich is a distant second.

2 Fly to Munich early in the day and spend the day and night in Munich and take the 1.75 hour train later train the next day. Even if for only one night Munich is worth the stay. When will you have the opportunity to do this again. You can buy the train ticket in advance this way which might save 10 euro on the cost.

3 Fly to Munich and transfer to the train station. By the time you are done with everything hotel to hotel the trip will take you 8 hours I suspect. I would only do this if I was unwilling to pay for the one stop Lufthansa flight that changes in Frankfurt and goes Paris to Salzburg in 3:75 hours.

The one nice thing about flying into Vienna is that you can take the train from inside the airport right to Salzburg, without having to change trains.

I chose to fly into to Vienna for my trip to Salzburg because it was easier, even though slightly longer, than flying into Munich. Plus, I have read about numerous train delays and strikes with the German trains over the last few years. For me, that is a negative.

An even better option in my opinion is to simply take the train from Paris to Salzburg. Flying to Munich won't really save you any time compared to the train and the train is much easier and more comfortable.

I'm with Badger. In fact, taking these trains have been on my list for quite a while now...

Thank you all for the information. I had looked into the train from Paris to Salzburg sometime last year, but at the time the trip seemed long and complicated--like 8+ hours and 4 changes between the two cities. Now that I'm looking at actual flight times, plus time at the airport, and transfer to trains, I can see that the time difference isn't that great. I do prefer the train myself, so maybe it's time to revisit that possibility. Any advice on which train site to visit since this trip will cross a number of countries? And is this the type of trip to book in advance just like I would a flight? Except for a Eurostar train between London and Paris twenty years ago, and getting ourselves from Milan to Varenna a couple times before our RS Best of Italy tour 8 years ago, I have zero experience with trains on the continent.

EDIT--I tried the Deutche Bahn website suggested by CJean and found trains with just one or two transfers. However, when the journey details are revealed, every TGV train starts from the Gare de l'Est and requires a reservation BUT it also says a reservation cannot be made because there are works going on and the train times will change. This is for June 14, so wait until closer to the date? Surely trains will be running....or not?

Start here, although it wrongly leans towards railpasses:

https://www.ricksteves.com/travel-tips/transportation/trains

Europeans think nothing of passing through multiple countries with a ticket from just one of the rail companies. Many posters on this board swear by DB Deutsche Bahn for everything, but I prefer to use the country I'm starting the trip from. The bar coded ticket can usually be printed at home. More modern customers download an app and get an E-ticket. If you have any faster trains, seat reservations are either required or (in June) advisable. Learn to use the rail agency website and to find notes like footnotes to a symbol that means "Seat Reservations Compulsory". Advance purchase can be vastly cheaper, but often no-change, no-refund, just like an air ticket. You might get the best advice here if you sketch out the entire trip, and the number of travelers. Also if a pop concert or family event is involved.

Your OP does not mention if you have the slightest interest in Vienna, a much richer destination than Salzburg. Both will be very crowded and busy in June. I personally would not go both places in one trip. Our fifth or so trip to Europe was two weeks, Innsbruck-Salzburg-Munich-Vienna. We had cheap tickets from Austrian Air, with two segments to get to Innsbruck, home from Vienna.

Every airline website will tell you their early check-in requirements. They can't tell you if the airport will be crowded, or if there will be a strike that day (Ironica typeface.)

Thank you all for the information. I had looked into the train from
Paris to Salzburg sometime last year, but at the time the trip seemed
long and complicated--like 8+ hours and 4 changes between the two
cities.

It can be done in a bit over 8 hours with one change. Although with two changes you can reduce the travel time a bit. There is also a direct overnight train that leaves Paris in the evening and arrives in Salzburg next morning.

Now that I'm looking at actual flight times, plus time at the airport,
and transfer to trains, I can see that the time difference isn't that
great.

Yes, this is a trip that will take time. Paris and Munich are two of the largest airports in Europe so navigating them can take some time. I don't know what your intinerary looks like but if you have the time, there are plenty of nice places along the route where you can spend a night. Personally I'd consider Ulm or Augsburg.

I do prefer the train myself, so maybe it's time to revisit that
possibility. Any advice on which train site to visit since this trip
will cross a number of countries? And is this the type of trip to book
in advance just like I would a flight?

As mentioned, www.bahn.de is the best place for this trip. And yes you should buy the tickets in advance.

This is for June 14, so wait until closer to the date? Surely trains
will be running....or not?

They will most likely be running, June is still far away and there is no reason to start worrying about train tickets yet.