In the pantheon of beloved fast-food fixtures, menu staples like fries, burgers, and chicken sandwiches tend to take top billing. But don’t discount the most important supporting character: the sauce.

A surefire way to keep menus interesting, and occasionally add a little heat, some fast-food sauces are so beloved that they’ve achieved icon status all their own, surpassing the popularity of the very menu items they’re served with.

While many of the most beloved sauces are long-retired, and others make temporary appearances as rare as Halley’s Comet, some cult classics have endured. Here are 7 of the most famous sauces in fast-food history.

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The latest fast-food sauce to make a comeback is none other than McDonald’s beloved—and sorely missed—Szechuan Sauce. From rarely seen holiday pies to McRibs and McLobsters, McDonald’s is the chain perhaps most well-known for toying with customers’ nostalgia, and this sweet and spicy dipper is no exception.

It initially debuted in 1998 to coincide with Disney’s movie Mulan, and was made with an addictive medley of soy, garlic, ginger, and mild vinegar, it’s been quite a while since the popular sauce’s last appearance. But that changes—for a limited time, at least—on March 31. Capturing the classic comfort flavors of American-Chinese takeout food, with a tinge of soy sauce and sesame, it’s easy to understand the obsession with this salty sensation.

As one reporter succinctly puts it, “Taco Bell, just leave it alone.” From Mexican Pizza to Crispy Chicken Sandwich Tacos, Taco Bell loves to tinker with its menu, sometimes taking beloved items away to the chagrin of customers, who mourn their long-gone favorites for years.

This was the case with the fiery Lava Sauce, but especially so with the long-lost Baja Sauce. The discontinued sauce, which has been M.I.A. for some years now, is a creamy, cheesy blend of peppers, garlic, dried onions, and vinegar, and packs a bit of zesty tang and tingle. It had such a cult following that an online petition was started to bring it back, and when grocery stores and retailers started selling versions of the sauce, discerning customers were having none of it—according to harsh online reviews.

As the single most popular hot sauce in America, it makes sense that Sriracha forms the base for one of the most adored sauces in Wendy’s history. The Spicy Sriracha Sauce arrived in 2015, during a time when Wendy’s was apparently going all-in on the rising trend, and quickly gained fans with its balance of rich creaminess and spice.

It was a go-to dipper for fries and nuggets, but hearts were broken in 2021 when it was discontinued and replaced with another spicy option—one that customers were not as keen on. The discontinuation was among the biggest menu changes for the chain last year, and the signature sauce remains sorely missed to this day.

In name alone, Mayo Onion Sauce doesn’t have the catchy flair of a Baja Sauce, or the trendy hook of a Sriracha, but this modest Jack in the Box sleeper hit is still one of the most popular fast-food condiments of all time.

Perhaps the simplicity of the sauce, made abundantly clear in its name, endeared it particularly well to mayo enthusiasts, who like their sauces on the milder, creamier side, with just a touch of zing from onions. It added the right amount of flavor and texture to any of the chain’s burgers, without overwhelming or distracting, and it was considered a key factor in taking certain menu items from good to great.

Alas, the Mayo Onion Sauce has been off the menu for more than 20 years at this point, but its wistful lasting legacy is evidence of its once-held stardom.

For better or worse, Burger King is one fast-food chain that’s made a habit of discontinuing menu items on the regular. While certain menu changes are for the better, others tend to leave customers scratching their heads.

The removal of the long-gone Chicken Fry Sauce falls into the latter category, holding such devotion that it too was the center of a Change.org petition. Initially making a menu appearance near the debut of Chicken Fries in 2005, the sauce was basically a mix of mayo, mustard, and barbecue sauce—in other words, this was like the Avengers-style super team of sauces.

It’s long since been discontinued, but that hasn’t stopped Redditors from desperately trying to replicate the recipe.

Now for some good news: not all of the most popular and iconic fast-food sauces have been lost to time! One underrated example is the Horsey Sauce at Arby’s, where the mayo-based condiment is as beloved as the roast beef.6254a4d1642c605c54bf1cab17d50f1e

A cute and catchy riff on horseradish, the main flavor in the creamy mayo sauce, Horsey Sauce has been a menu mainstay just about as long as Arby’s sandwiches. With just a hint of pungent spice and a dash of salt and sugar to make it extra addictive, the sauce is known to pair particularly well with roast beef, though lots of customers also love it on burgers and as a dip for fries.

A common theme among America’s most popular fast-food sauces is mayo. Whether mingling with mustard, onions, or Sriracha, the creamy condiment presents a broad canvas of flavor opportunities and dipping options. And one of the nation’s most popular fast-food chains is fully on board.

Chick-fil-A’s most popular sauce is also its namesake: the Chick-fil-A sauce. It’s a little smoky and a little sweet, with that dippable mayo quality and a bit of tomato tang, which pair perfectly with fries and nuggets. It’s so desired, in fact, that the chain has expanded its condiment line in grocery stores nationwide, to meet the growing demand for Chick-fil-A flavor at home.