Can I connect one Apple TV to two TVs with an HDMI splitter?

• An HDMI splitter would send the same picture signal to two screens. The TVs wouldn’t be independent.
• Regular HDMI cable has a maximum length of just 10–15 ft (for 4K content). The screens can’t be too far apart. You would need specialty cables for longer distances.
• Operation will stay with the one Apple TV box.

Other than that, you can connect like that.

My mention of smart TVs refers to HDMI-CEC features - a splitter might not allow this - see

If you can't control your TV or receiver with your Apple TV Remote – Apple Support (AU)

I use an HDMI switcher to switch between a TV and a projector. A splitter should also work, although some "smart" TVs might not co-operate!