Most Americans are under the mistaken impression that the shows they watch on television are American originals that inevitably get copied by nations the world over. While the USA may in fact lead the world when it comes to primetime, many of the most-watched shows of the last decade (and some even earlier) have been facsimiles of foreign shows. Some may surprise you, others may not, but these 15 American television hits all had their origins overseas.

The Office – The Office (UK)

The Office has been one of the most successful shows of an era, which is odd considering the format of the show and its awkward beginnings. After the initial shock of seeing a show that appeared to be a documentary but acted like a sit-com, viewers quickly became fans, and the show blossomed into a full-blown hit.

Out of those initial viewers, only a handful ever seemed aware that the show they were watching was a copy, character for character, of a show that ran on the BBC for only 14 episodes in 2001.

American Idol – Pop Idol (UK)

Just about everybody is well-aware by now of head-judge Simon Cowell’s jet-setting lifestyle by now, as he’s become known for his role as king of the televised talent show. Despite that, many Americans were surprised to find out that there was a long-running British equivalent to American Idol called Pop Idol. The BBC-run show predated our version by a full year, and Cowell has been dividing his time between them, along with later additions like X-Factor and Britain’s Got Talent, ever since.

Trading Spaces – Changing Rooms (UK)

TLC’s recent boom in programming has been much-loved by home-owners and value-shoppers alike, but you’d be hard-pressed to find one that knew some of their favorite shows were originally from the UK. Trading Spaces is one of them; the show began its life as Changing Rooms, and ran on the BBC from 1996 to 2004. Another little-known fact: What Not to Wear was also a BBC original, dating back to 2001.

Ugly Betty – Yo Soy Betty, la Fea (Colombia)

Most fans of this show (now sadly over) never took note of the small subtitle in the opening credits starting with the words “based on” — but those who noticed were usually quick to look up the original namesake. Yo Soy Betty, la Fea (I am Betty, the Ugly) aired in Colombia back in 1999, and the show was so immensely popular that endless re-runs over the years drove network execs here in the States to draw up plans for their own New York version of the South American telenovela. While the show only ran for about two years, the telenovela format and scheduling allowed for well over 300 episodes — something that’s sure to make Ugly Betty fans jealous.

Sanford and Son – Steptoe and Son (UK)

Any fan of Sanford and Son who wasn’t already aware of its English origins is sure to be surprised by the video above, showing a clip from the original BBC-run Steptoe and Son. The show’s surly antihero, played by none other than Redd Foxx, was billed as the black community’s answer to Archie Bunker, while the English version centered around the hardships of a pair of struggling white Englishmen. All differences aside, both shows were smash hits.

Supernanny – Supernanny (UK)

This one should be obvious, but it’s always surprising to see just how many people don’t see what’s right in front of them. Supernanny is a bit different from the rest of the shows on this list in that the star and supporting crew are the same on both sides of the Atlantic. The show began its life on the BBC in 2004, and after considerable success it came to the US. Other countries who picked up the show’s format had to find their own localized nanny, but Jo Frost serves as the heroin in both US and UK versions of the show.

Wife Swap – Wife Swap (UK)

Wife Swap began its life on the BBC in 2003, but ABC began to run an American version of the show in 2004 due to the show’s surprising success and marketability. Stateside, it even managed to spark a bit of a network-war when Fox retaliated with its own version, called Trading Spouses. The announcement spurred legal battles that led to Fox’s ultimate decision to bow out and scrap the show.

Big Brother – Big Brother (Netherlands)

Spurring legal battles of its own due to its namesake, Big Brother made its debut in 1999 in the Netherlands. The show’s name and format were immediately scooped up by every major network in the world, leading to scores of countries with localized versions of their own — including the US. Because of its widespread adoption, this show has become the most international of all the shows on this list.

Dancing With the Stars – Strictly Come Dancing (UK)

As a show with a distinctly American feel to it, it’s a bit startling to learn that Dancing With the Stars is not an American invention. The show’s predecessor, Strictly Come Dancing, debuted on the BBC in 2004 — as a reinvention of a British ballroom dancing show that had run for 50 years. Like a couple of the other shows on this list, the first thing you notice in watching the clip is that the show is exactly like the American version, from the set to the font in the title splash.

Deal or No Deal – Miljoenenjacht (Netherlands)

Miljoenenjacht, while fun to say (over and over again), is probably much more fun to play, considering the original show had the highest actual payout of all its syndicated children. Airing in the Netherlands since 2000, the show has since made its way around the world as Deal or No Deal — with an occasional Howie Mandel thrown into the mix. While certain aspects of the format were changed with every iteration of the show, one thing has always remained the same — the models.

Survivor – Expedition Robinson (Sweden)

Another reality show surprise — Survivor was actually based on Expedition Robinson, a Swedish-run show put together and planned by British TV execs in 1997. The show was a huge success, and it wasn’t long before the format was licensed out to CBS to start the now iconic American version of the show.

Three’s Company – Man About the House (UK)

Yes, Three’s Company was actually a mirror of a show that ran in the UK a full four years prior to its US airing. The UK version — Man About the House — was almost exactly like what we’ve come to know as one of the best sitcoms to come out of the 70′s. The biggest difference? The girls in the UK version were hotter.

All in the Family – Till Death Us Do Part (UK)

If Sanford and Son surprised you, then All in the Family might give you a heart attack. Both shows were brought to the US and reassembled by a man named Norman Lear, who seemed to have a flair for recognizing shows that could translate from the BBC to the American television. When it came to All in the Family, Lear nabbed the guts of the UK’s Till Death Us Do Part. Archie Bunker was a perfect choice for the role he played.

Cash Cab – Cash Cab (UK)

Most people think that Cash Cab started out as a hobby carried on by Ben, the show’s educated cabbie, until he got picked up by the Discovery Channel. Few ever look into the show’s history, otherwise they’d know that Ben Bailey is actually a stand-up comic who was cast by the network to play the role of a cabbie, in a syndicated copy of a very international show that started in the UK. The show has the same name in every country.

Who Wants to Be a Millionaire?

Last but not least, Who Wants to Be a Millionaire? is one of America’s biggest game shows. It may be past its prime now, but it wasn’t long ago that this show was so huge that it spanned not only the pages of TV Guide, but also newspapers, magazines, and TV news reports across the country as well. What most people never realized (unlike The Weakest Link) was that the show was yet another copy of an originally British game show of the very same name. The show began its run on the BBC in 1998, and considering conversion rates has a far higher payout than its American counterpart.