What to do in Paris on May 1, when almost everything is closed?
We have tickets for King Tut at 9 AM but are at loose ends from noon onward.
I've reviewed the list of the few museums open that day but none really appeals, except perhaps the Catacombs.
The metro will be open but operating on a holiday schedule.
I like walking, both through city neighbourhoods and green space. We will avoid areas with May Day demos or "gilets jaunes" presence.
Batobus on the Seine is a faint possibility.
How would you spend a free day in Paris?

Except for total museum addicts, finding things to do on May 1st is not at all a problem. For about the last 3 years, the weather on May 1st has been absolutely foul, though, so maybe we'll get lucky this year.

If you have never visited any of the big cemeteries -- Père Lachaise, Montmartre, or Montparnasse -- this would be a good day to do it.

Unfortunately no. We leave by TGV for the Drome region on Sat May 4!!

Walk around, be a flâneur. You might even see this:

Protest and riot? Sure yellow vests will be out in force. Kind of exciting time to be in Paris for me at least.

The only things closed are museums and shops. There are plenty of other things to do, you could go see any church you wanted, for example, but I'd probably do something outdoors. There are many parks in Paris, one could do any kind of theme for a neighborhood or architectural walk (if you had any such interest, of course), the cemeteries are a good idea if you like that kind of thing, a boat cruise, etc. I always like to do walking tours of neighborhoods based on particular interests of mione, maybe you have one. For exdample, an Art ;Nouveau walking tour in the 15th where there are a lot of Guimard buildings. All walking tours are pretty much just outside looking at things. I like to do ones listed in one of the entertainment guides under Conferences, but those are in French. However, there are some companies that do walking tours in Paris that are in English, if that's the only language you understand. Various themes like Medieval Paris, WWII Paris, Jewish Paris, etc. Those come out on Wednesday so one can't find them now but I suspect there will still be plenty on May 1st, probalby like most Wednesdays. They are having some today, after all, and it's a holiday. Here is the list for this week

https://www.offi.fr/visites-conferences

I find this one kind of interesting:
ge d'or de la presse parisienne : l'histoire de l'ancien quartier de la presse de la Belle Époque parisienne.
ge d'or de la presse parisienne : l'histoire de l'ancien quartier de la presse de la Belle Époque parisienne.

• Programmation : Mardi 23 Avril : 10h30, 15h00. Tarifs : 12€. Conférencier : Pauline Lebourcq>>

or this Enclaves bucoliques cachées des Batignolles à la Cité des fleurs. Villas secrètes. Maisons de Brel, Barbara, Simenon.
Enclaves bucoliques cachées des Batignolles à la Cité des fleurs. Villas secrètes. Maisons de Brel, Barbara, Simenon. Programmation : Mardi 23 Avril : 14h00.

• Tarifs : 12€. Conférencier : Jackie Moreau>>

If you don't understand French enough, just go to Viator or something, there are many walking tours, you said you liked to walk. Or do it yourself, there are lots of guidebooks and online information for such a thing. The ones in English tend to be pretty routine, though, not as many niche or interesting walks (companies that do those). But Pariswalks has several on May 1st, one of Gobelins and one of the center islands in the afternoon.

That King Tut thing kind of takes up the first half of the day, though, or you could have done a day trip elsewhere, there are lots of things open on May 1st that are worth a visit by train. For example, the Chateau de Chantilly is open every day, including holidays. Malmaison is a really nice visit, also and it's open on May 1st.

We will be there and since one of our opera performances was cancelled I was just telling my Husbear we need to find something else to do. But, sorry, I realize your post was directed specifically at Ted and I would not think of intruding.

The Guimard Art Nouveau buildings are in the 16th. There's also lots of Art Deco to look at. This Facebook page might give you some ideas,
https://www.facebook.com/parisartdeco/

Buy bunches of muguets des bois!

We do have a French-language walking tour booked on May 2 through Paris Greeters, a wonderful organization of volunteers. We send a donation to the organization after our tour; the volunteers do not accept payment.
Thr walking tours -- which have always turned out to be one-on-one, though that is not guaranteed -- are great neighbourhood overviews, with an architectural, sociological and historical flavour.

Great suggestions

A sidebar question for Kerouac or anyone else with a direct knowledge of the Yellow Vests situation:
Fodorite friends were in Paris this past weekend during the most recent demonstrations and reported widespread disruption of metro and street traffic. One woman had 3 Ubers "bail" on here when she tried to go from the Latin Quarter to the Right Bank. Another reported widespread gridlock on the Right Bank.
(I was particularly surprised at the widespread metro closures reported this past weekend.)
I won't be staying anywhere near Place de la Republique or the Elysee or the Arc de Triomphe or Notre Dame.
I'm in the N Marais just off the rue Charlot. On Saturday May 4, I will need to get to the Gare de Lyon for a 9:40 train.
I can Uber or take the 91 bus.
I assumed that in that remote location and at that early hour (8:30-9 AM) I would not be affected.
One of the above ladies said I should prepare for the worst.
Any views of how widespread the traffic and transit disruptions tend to be?

There was a lot of disruption last Saturday because the Facebook yellow vest movement, or at least its final hard core members, named the day "Ultimatum 2" and said that there would be insurrectional violence throughout the city and that no area would be safe. It turned out to be a hollow threat, but the police and gendarmerie preferred not to take any chances in light of what happened on certain other Saturdays.

Since the yellow vest movement has often made a point of gathering in unannounced places to try to catch the police and gendarmerie off guard, you cannot believe any announcements that are made in the media.

Gare de Lyon has been one of the main arrival points of the yellow vests over the last three months, but in the morning, that's all they're doing -- just arriving. Before 10am, they can be considered harmless.

Very useful info -- thank you.