I am thinking of taking my mom to the opera this November while we are in Paris. Being from Seattle our theater dress can be rather casual.
Has anyone been and can tell me how formal is the average person there dressed?
Thanks!

I attended an opera at the Opera Garnier in June 2005, many people were dressed casually.

It isn't formal, a nice simple dress or skirt and blouse are fine, or even decent slacks and pretty blouse. I would not wear outdoorsy casual grubby stuff, nor very casual garb that is sporty looking or masculine, etc (like cargo pants).

How great to be attending the opera in Paris! You can get away with casual but I'd take advantage of the opportunity to dress up a little -- makes it an even more memorable, special occasion and makes for some great pictures. (also gives you a fine excuse to do fine dining beforehand...) When I'm packing, I often think it's a pain to take along a dress and a pair of heels for just one night, but I never regret it once I'm there. have fun!

My wife and I ceased to worry about the dress question after our first trip to the Opera Bastille. We had expensive seats and decided that we should dress appropriately. I took a suit, dress shirt, and a tie. My wife had her best outfit.

When we were seated I noticed that the man next to us was dressed very formally, in a black T-shirt.

You can dress any way you choose. I went to an opera at Garnier on the spur of the moment and had no choice but casual. People were dressed in the whole range much as happens here (Denver). I would say that the average person is in 'average' dress. There is some formal dress, mainly in the orchestra and a lot of very casual.

Don't miss the opportunity to go because of clothes. The French understand how to perform opera and appreciate it.

Thanks all for the help! I can always squeeze in my little black dress and heels. Just wasn't sure if it was dressier than that.