Your options depend on what connections your TV offers. For just using you headphone the common one being headphone mini-jack, which usually has the volume controlled via the TV, and it some times automatically mutes the TV's speaker. You can get appropriate headphone extension cable at various electronic, or music stores, maybe even your computer store. Guitar Center will sell you a 10' extension cable for $9. You might also need a headphone plug adapter for different size jack.

Other options which require additional equipment are analog audio output through RCA connectors which is also a common connection option, and which can either be variable volume controlled by the TV, or have the TVs volume output fixed. Often you can select either mode in the tv's setup menu. Some TV's also offer digital output via optical cable. And then there is HDMI.

Using the RCA analog output to connect to an audio receiver or amplifier, and then connect headphone to that for independent volume control, offers better sound, and more flexibility with the volume.

You can do the same thing with a (optical) digital output, but it needs to be connected to a DAC or receiver that has one incorporated. This would usually be the best sounding connection.

Another different option might be relatively inexpensive wireless headphones ($30-$100) designed to connect to a TV, usually to a TV's headphone jack.