The short answer is “Maybe”.
Details:
The US and the UK use two different (analogue) video formats. The US uses “NTSC”, and the UK uses “PAL”. (I will leave HDTV out of this, as it does not apply to DVDs. Yet.)
Fortunately, DVD players exist that will play DVDs using both formats.
Unfortunately, these players are more common overseas than in the US.
Fortunately, they can be found in the US and Canada, at least in shops in large cities. A web search is also helpful. I, for example, have a JVC player that, while designed for NTSC, will play PAL discs.
Unfortunately, because of another wrinkle, I haven’t found any PAL discs to play in it.
Hollywood lawyer types introduced a system of “regional codes” or “zone locks”. They wanted to control the flow of movie discs, so that DVDs of a movie released in one zone wouldn’t be taken to another zone where the movie was still in cinemas and cut into cinema sales.
Their solution: divide the world up into zones, and assign a number to each. The intent was to label each DVD disc with the numbers of the zones where it was intended to be sold. The DVD player would have a zone number indicating where it was installed. (In practice, the player’s zone number indicates where it was sold.)
The Hollywood lawyers pressured the DVD-player makers into making DVD players that would read the zone numbers of the discs, and refuse to play a disc that did not have a number matching the player’s number. Then they released their movies on DVDs with different zone numbers in different markets.
The US and the UK are in different zones; the US is zone 1 and the UK is zone 2.
The upshot of all this is that, even if you bring a disc back from the UK, and even if you have a player that can play UK discs on a US television set, the UK disc must have the US zone number on it; otherwise, the player will not play it.
I’m still looking for a Zone-1 (North America) PAL disc.
Of course, people weren’t going to put up with this nonsense. “Zone-free” or “multi-zone” players soon appeared, which could play discs from any zone. These are available overseas and in specialty stores (although you may need to do quite a bit of digging to find them in the States).
It is also important to remember that the zones are completely optional for the makers of discs; it is perfectly possible to release discs worldwide to all zones. More disc producers should do that.
Happily, consumer-level DVD-production gear doesn’t have to deal with zone locks (although it has other issues, notably a format war among different types of recordable discs).