Average Paris Lines in June

Get a Museum Pass which lets you use a short line for the Orangerie, Louvre, d'Orsay and a few other spots. Get to Notre Dame about an hour before it opens for the tower climb -- for entry to the Cathedral the lines are never significant -- I don't think I have ever waited more than 5 minutes -- even with a big crowd it filters in quickly. Ste. Chapelle usually has long security lines and usually the pass doesn't get you advantage but sometimes they have a separate line

I've looked into the Museum Pass but it doesn't make sense for me because of how I'm splitting up my days (it's significantly cheaper for me to just pay the entrance fees and b/c I'm a college student I can't easily pay almost twice the normal prices just to skip a few lines), so I just want to know what I'm getting into even if I can't change much. And that's good to know about St. Chapelle, thanks!

Arriving early or late is usually a good way to avoid the crowds. For the Louvre, you can try using the Metro entrance instead of the glass pyramid.

ETA: Get the museum pass even though you're on a tight budget. Your time in Paris is extremely valuable and the pass will literally save you hours of idle, frustrating time waiting in lines. It's what Hodor would do.

I also would re-think the Paris Museum Pass. Buy it once and you're done pulling out your wallet AND you're avoiding lines. A 6 day pass is 82 dollars. And it would cover almost all of what you want to see and it would cover other random stuff you might walk by and get to wander into.

Even if you don't buy the Paris Museum Pass, you can still buy tickets for several sites online and skip the line. Check the websites for the Louvre, and there's a combo ticket for the Orsay and Orangerie on the Orsay website, or go to a FNAC store when you arrive in paris and buy the individual tickets there. You'll pay a small fee per ticket but nothing like the entire museum pass, and you will still get to skip the big lines.

Kim beat me to it, as I was going to suggest the same thing - if you don't get a Museum Pass, buy advance tickets for the "biggies." This way, you get to use the same entry as Museum Pass holders.

"getting to St. Chapelle first thing in the morning"

This is very important. The hold-up here is not the ticket line, but the security check (it's now in the same place as court buildings, so everyone has to go through security to get in). And by going early, you actually get a seat so you can sit and enjoy the beauty before the mobs (it's a small place and fills up). If there's one place that worth missing breakfast for, it's Ste-Chapelle.

Thanks everyone :)

I'll make sure to buy the tickets ahead of time that I can. My sister can get me into the Louvre for free and I'm seeing a few of the other sights on a free Sunday (but I've made sure that those are ones that I care less about so I can just skip them if the lines are too long to be worth it) - with that combined with how my trip is laid out (I'm there for 4 days but separated by a trip to Italy b/c of my sister's schedule), covering my trip with a Museum Pass would be over triple what I'd pay for everything individually so idk if I can justify that, but I'll definitely keep it in mind for future trips.

Here are my current plans for avoiding long lines at my top priorities (in the order I'm planning on seeing them) - if anyone has thoughts on what I could do better I'd love to hear them!
1) Orsay - buy tickets at FNAC, go later in the afternoon (still giving myself 2.5 hours before closing)
2) St. Chapelle - go right before opening, maybe getting there at 9 for a 9:30 opening time (and can I buy tickets ahead of time for this as well?)
3) Notre Dame - I'm planning on going after St. Chapelle bc it's slightly less important to me, but I'll see how the lines are and try to come back later or on a different day if they're too awful. I'd love to climb the towers but I've heard that that line moves super slowly so I'll probably have to put that off for this trip.
4) Eiffel Tower - planning to climb the stairs in the afternoon
5) Louvre - going after 6 to avoid crowds, plus that's when I can get in for free
6) Orangerie - get there early in the morning because it's a free Sunday (if it opens at 9, should I get there earlier than 8:30? And how bad do you think the lines will be if I sleep in a bit and get there closer to 10? Would it be better in the afternoon?)
7) L'Arc de Triomphe - going in the evening, but on a day when Le Champs Elysees is car-free so it might be crowded (in which case I'm fine just looking at it and not climbing the steps)

I'd also love if anyone could tell me whether my guesses about wait times (below) are in the right vicinity or if they seem way off:
1) Orsay - 30 minutes for afternoon entry, tickets bought ahead of time
2) St. Chapelle - 30 minutes for getting there before opening
3) Notre Dame - 45-60 minutes around 10 am on a weekday
4) Eiffel Tower - 15-30 minutes for stairs
5) Louvre - 15-30 minutes for evening entry from a side entrance
6) Orangerie - 30-45 minutes first thing in the morning, 60 a bit later on

When you go to FNAC get all your tickets at once; be sure to get 'anytime tickets' if possible and you won't be held to a schedule. You pay a bit more getting them at FNAC but then you don't have to worry about the longest lines. The Orsay is the worst. For free Sunday use it to go to the less popular museums; it is ridiculous at the Orsay and I don't think the Louvre has free Sundays in summer only in winter.

sorry....what is FNAC? I would like to buy Orsay tickets in advance. Thank you.

@RGS FNACs are stores where you can buy some tickets ahead of time (as far as I understand). Here's a map of their locations: http://www.fnac.com/localiser-magasin-fnac/w-4#bl=chMag

@somewhat slightly dazed -- You shouldn't have to wait anything like 30 minutes if you have an advance ticket, more like 5.

When you arrive at the Orsay museum and are looking at it head on (with the river on your left), the entrance for advance ticket holder ("munis avec billets") is to the RIGHT of the building, Entrance C.

The huge lines you will see are for the folks who are waiting in line to buy tickets. You go up on the right-hand side of the front and have a much shorter line.

FNAC stores sell everything from books to computers to small appliances to mobile phones to CD's and DVD's. Many of them also have a ticket office (like the old Ticketron offices in the US). They sell tickets not only for museums, but also concerts. theater events and the like. They have branches in many western European countries, including Spain, Portugal, and Switzerland, as well as stores in most French cities of any size.

Very handy for all kinds of things, and fun to browse (I've bought some CD sets that were much cheaper there than in the US, although the converse is equally possible).

If you want to climb the Towers of Notre Dame, you need to be in line about 30 minutes or so before it opens. I've had appointments nearby at 08h30, people were already lining up and an hour later, the line was 2 blocks long and not moving. Because only a certain number of people are allowed in at any one time - and they have to exit before anyone else can go up - the timing becomes complicated.
On the other hand, the line in front of the Cathedral to view the interior is deceptive. Most people just do a quick run-through, so this line moves quickly. I've never waited longer than 15 minutes, even when I thought it would take an hour to get in.
The lines at Sainte-Chapelle close for lunch, so it's not a good idea to go at that time. In any event, you should hope for a sunny day, which makes all the difference in the world.
Buying advance tickets for Musee d'Orsay allows you to enter via the entrance C, to the right just past the regular admission lines. You pass through a quick security check and you're good to go.

Also, if you want to climb the stairs to the Eiffel Tower, you won't have long to wait. Make sure you look for the right place to buy tickets for that, and if you want to go to the top, when you reach the platform level, you'll have to buy another ticket to take the elevator all the way up.

This all sounds great, thanks! I'll plan on skipping the ND towers in that case, since it would be cool but probably not worth spending hours in line. I'm glad that the other lines will likely not take that long in general.

For the Orangerie, that's the only popular museum I'm planning on visiting on the free Sunday - will that wait be ok if I get there relatively early or should I go on a normal day to avoid the crowds? (I was initially going to do the Orsay on a free Sunday but realized that wouldn't be worth the money saved, so idk if it's the same situation with the Orangerie or if that one's not as bad crowd-wise)

When something is "free", it's going to be crowded - especially if it's raining.
I avoid "free Sundays" like the plague - but I'm even more allergic to waiting in lines than you are.

Use the Carousel entrance for the Louvre. When you get to Notre Dame, take a look at the tower line. You might get lucky.

Put the Carnavalet Museum (in the Marais) on your must-see list. It's a very good museum and it's always free. It's a 15-20 minute walk from Notre Dame.

There's on-going construction at the Carnavalet, and this will continue for a couple more years.
Some wings and permanent expositions might not be open when you arrive. Check the official Carnavalet website to see if what's open will interest you. You do not pay for the permanent exhibits, though a donation is now requested, but any temporary exhibits will require you to pay for a ticket.