how late can you stay out in Paris ? Is 11.30 pm too late ?

Not sure when you are traveling but we just returned and were amazed the sun doesn't actually set until 10:30 or so.. We were typically walking back to our hotel around then and we had our children (10 & 13) with us. I don't think its "late" for the french.

11:30pm is not too late in any world-class city like Paris, NYC, London, Barcelona, etc. Many people like to go out (and stay out) in the evenings. I would also familiarize yourself with the public transit system (there may be no need for a cab).

What day of the week, time of year? In the summer, there will probably be people out much later than that, especially on a weekend. In the winter on a weekday? I'm not sure.

It makes sense to stick to main roads/lit places.

We found ourselves out in Paris very late - the better part of 2am - and unable to find a cab to take us back to our hotel. It was a long walk. It felt fine, but I was with DH and I don't think I'd like to do that alone. But with someone, no problem.

I wouldn't bother with a cab. The metros run till about 1 am or thereabouts and are full of people and quite safe. We often return to apartments at midnight or later without any nervousness. Safety is not something to worry about in Paris; certainly not before midnight. We always stay in outer arrondissements now and so are often taking long metro rides late at night to return to the apartment. Never in numerous trips have had any issues at all. A stroll by the river late at night is a treat. We walked around Notre Dame at night in the rain at midnight only last month.

Always safe if you protect your valuables.
I have never had a problem getting a cab late at night.
Go to the nearest busy intersection, look for a taxi with a green light on top.
Print out the address where you want to go, including the Postal Code, so there won't be any confusion.
Ask if the taxi takes credit cards before you get in, if you need to use them.

I would have no problem with being out in Paris at 11:30PM - at least, in areas where you are likely to find tourists. As in any city, there are neighborhoods to avoid, but those should be fairly obvious. I know I've been out that late a few times in Paris without worries.

Take a smart phone, and you can find the best bus or metro from your current location back to your hotel at any time. Try one of the Paris RATP apps. Google Maps works too though on my last to Paris visit in May it had a few inaccuracies.

We were out until almost 12:30 am back in late April...our airbnb was walking distance from the Eiffel Tower. We were a little more 'aware' of our surroundings and stuck to better lit places, but didn't feel ill at ease. And can I say Trocadero was bustling even at almost midnight. (It was a Friday). There were even some snack trucks there where we got some popcorn!

Safe even on public transportation. Just use good common sense.

Contrary to popular belief, the sidewalks of Paris do not roll up by 11 PM.

One of the great joys in Paris is walking around after the lights go on.
The whole city changes - try it sometime - you will be positively delighted.

Most tourists stay in the touristy areas, so there's nothing to fear If you keep your valuables safe, especially on the Metro or Bus.

All the petition girls and amateur pickpockets will have been picked up and gone back to their camps.

If you happen to go down a deserted street, nobody will jump out to harm you. It's just that all the businesses are closed.

If you happen to see a homeless person, he or she will be most interested in getting some sleep, and won't bother you.

We felt like Paris was a city that never sleeps in the historic areas at least. We were often out until midnight and were in good company with lots of others, which made it feel safe. My husband and his buddy took a walk one night around 1am and didn't have any issues.

We were there last week and I don't think 11:30 is too late to be out either. I never felt unsafe, walking back to our hotel or on the metro.

11:30 almost seems too early to go to bed in Paris, especially in July when it'll be light out until after 10pm. You'll find yourself eating later than you're probably used to, and the best thing in the evening afterwards is to walk, and then walk some more. Be sure you have comfy walking sandals. I've never felt uncomfortable. If you're staying in RS's suggested Rue Cler neighborhood, though, it's less central and you have to walk longer through less interesting (but still safe) areas, so you'll want to learn about using the Metro.

Good luck getting a cab after midnight if it is raining (or before midnight, for that matter.) RATP website contains info on all-night bus routes but they may not be convenient for where you are staying. I'd give yourself a midnight deadline for a Metro ride.

I was at a friend's apartment until 1:30am by Gare du Nord. He advised me to use an Uber rather than a taxi and it worked great.

Two years ago, my husband and I walked from the Eiffel Tower back to our hotel near Plaza de Republique (about 4 miles) around midnight and I did not feel unsafe at all. Of course there were police/military at the bridges, but there were still people out walking or at restaurants etc. It was somewhat magical to be out then.

A lot of Europe doesn't get rolling until about 10pm and midnight is hopping so I think I would have not reservations about being out at 11.30. You might avoid dark alleys. When the bus tour ends, ask the driver or guide for best spot for a taxi. My guess is that taxis are in high demand at that time of night.

Before the kids were born we used to walk home at four or five in the morning, across Paris, after being out dancing. We were too poor for a cab but our legs were young. In recent years, we caught a cab a 2:30 a.m. after a wedding. We had to walk to the closest cab stand, which was at Opera. Tons of people out. Lots of people flagging rides. Midnight is early in Paris.

If you want to take a taxi, you can either go to the nearest busy intersection, or a large cafe or restaurant or even a theatre.
Lots of taxis looking for fares after midnight. Just look for the green light on top.