CORRCTION:  I am looking to ADD wireless headphones

I do this already.

Use a Sonos Port with a Bluetooth TX linked to either the digital or Analog line-out. Some examples are the Fiio BTA30 Pro or 1Mii B03 Pro… then play the Sonos Audio, such as Sonos Radio etc; to the Port, grouped with your chosen Sonos speakers and use either Bluetooth, or wired connected headphones, linked into the BT TX and then you can listen on both speakers and your headphones - note you can use two pairs of headphones with some TX devices too.

Ken,

That is a perfect solution.  I would LOVE the option to add TWO headphones at once.  Are you saying that I will need to purchase TWO separate pieces of hardware?  Can you possibly let me know exactly what I will need to purchase?  Thank you so much!

The Sonos Port is the link in/out of the Sonos ecosystem, so that’s required. Then simply add the Transmitter of your choice with either RCA analog input or S/PDIF coax input and that transmitter just needs to connect to your headphones.

A cheap long-range BT TX is the 1Mii B03 Pro - the better TX is a Fiio BTA30 Pro - then you can use your chosen Bluetooth Headphones - I use Sony Headphones currently, but I’m giving those to my daughter and switching over to the Sonos Ace in the near future, as I have a Sonos Arc soundbar and those headphones work with that soundbar for TV audio playback in sync.

Thank you so much for that!

Anyone have any other solutions that might be a little less costly?

Its a shame the new Sonos headphones dont integrate with the rest of their products aside from the Arc. I too have been looking for a solution to where i can both use headphones while my speakers play the same and/or seamlessly switch from my headphones to my speakers.. I'm in shock the new Ace headphones dont do this.

How about a different option…  is there a way to use WIRED headphones off of one of my wifi speakers and still play my music from my other speakers with the headphones? 

No, not really.

You could potentially connect a set of ‘wired’ headphones to the line out (line level) on a Sonos Port. Or, the gen 1 PLAY:5 (S1 only) has an actual headphone out port, which disappeared on the gen 2. Then you could play other music on the other Sonos speakers, while playing your headphone music on the Port (or PLAY:5 gen 1)

Sonos hasn’t been designed for headphone use until the Sonos Ace and its connection to the Arc. That could possibly be changing, but I’m not sure about Sonos’ unannounced plans. 

Thank you so much!