Mustard is a condiment made from the seeds of a mustard plant (white or yellow mustard, Sinapis hirta; brown or Indian mustard, Brassica juncea; or black mustard, B. nigra). The whole, ground, cracked, or bruised mustard seeds are mixed with water, salt, lemon juice, or other liquids, and sometimes other flavorings and spices, to create a paste or sauce ranging in color from bright yellow to dark brown.
- Bertman Original Ballpark Mustard created by Joe Bertman in Cleveland is a spicy brown mustard used for more than 90 years at sports stadiums in the Cleveland, Ohio, area and is also sold at retail.
- Boar's Head produces an delicatessen style mustard from an old German recipe that combines white wine and horseradish. The company also produces an Honey Mustard.
- Charroux (based in Charroux, Allier), one of the oldest mustards in the world, traces its creation back to monks from the Bourbonnais in Auvergne, France more than 900 years ago.
- Colman's, a British company and brand, is one of the oldest existing food brands, famous for a range of products, almost all being varieties of mustard. It is a subsidiary of Unilever.
- Düsseldorfer Löwensenf is a German company and brand. The company was founded in 1903 in Metz (then part of the German Empire due to the outcome of the Franco-Prussian War), and is famous for its Düsseldorf mustard.
- French's is an American manufacturer and brand of prepared mustard: French’s "Cream Salad Brand" mustard debuted to the world at the 1904 St. Louis World’s Fair.
- Fallot is a Dijon mustard from the Burgundy region in France.
- Grey Poupon is a brand of Dijon mustard which originated in Dijon, France. It is now manufactured by Kraft Foods. Like other Dijon mustards, Grey Poupon contains a small amount of white wine.
- Gulden's is the third-largest American manufacturer of mustard, after French's and Grey Poupon. The oldest continuously operating mustard brand in the United States, it is now owned by food industry giant ConAgra Foods. Gulden's is known for its spicy brown mustard, which includes a blend of mustard seeds and spices. The recipe has stayed a secret for more than 140 years.
- H. J. Heinz Company produces a brand of prepared mustard.
- Händlmaier is a German maker of Bavarian-style sweet mustard.
- Hawkshead Relish is an English Company
- Keen's is a brand of McCormick Foods Australia Pty Ltd. Keen's Mustard Powder is created from finely crushed, high-quality mustard seeds.
- Maille is a French mustard and pickle company founded in 1747 in Marseille, when it made mostly vinegar. Later, it became well known for its Dijon mustard and cornichon and it subsequently opened an establishment in Dijon. It is a subsidiary of Unilever.
- Meaux - Moutarde de Meaux, aka Pommery is a Dijon mustard.
- Les Trois Petits Cochons (Three Little Pigs), a charcuterie company located in Brooklyn, produces a Dijon and a whole grain mustard. 
- Plochman's, an American brand of mustard made by Plochman, Inc., is recognizable by its barrel-shaped bottle.
- Podravka, a food company based in Koprivnica, Croatia, produces a brand of mustard.
- Sassy Mamas Mustard is a handcrafted artisan mustard made from yellow, brown, or black mustard seeds. Started in 2015 in Temecula California by Kat Ellis and Shawn Smoot.
- Stadium Mustard is the trademarked name of a brown mustard served in stadiums and arenas throughout the United States. Manufactured in Illinois since 1890, it is made with a brown seed. It is a mildly spicy brown mustard more similar to European mustards than American deli-style brown mustards.
- Taylors is an 1830s brand prepared English mustard that claims the title of "the first English Mustard to be sold Ready Prepared", now made by Walter Black Foods in Glasgow, Scotland.
- Tewkesbury mustard is a blend of mustard flour and grated horseradish root that was developed in the English town of Tewkesbury in Gloucestershire, and gained a certain notoriety in the 17th century, becoming a staple condiment of the kitchens of the time.
- Thomy is a Swiss food brand owned by Nestlé; it produces mustard and other condiments such as mayonnaise and salad dressings.
- Turun sinappi – a mustard made in Finland, it is often used with makkara (i.e. sausage).
- The Tracklement Company Ltd. made the UK’s first commercially available wholegrain mustard in 1970 and now has a range of 11 mustards.
- Williams-Sonoma produces a variety of beer mustard.
- Woeber's Mustard Springfield, OH Since 1905. A fourth generation family company making mustard, vinegar, and horseradish products.
- Zatarain's, a company based in New Orleans, Louisiana, produces mustard and other condiments and spices.
A ceramic mustard bottle from Maille, circa late 19th century
- "Delicatessen Style Mustard | Boar's Head".
- Charroux Mustard: The Ultimate Handmade Mustard of France - Zalmo.com
- Bare Barging in Burgundy: Boating, Exploring, Wining and Dining. Erasmus H. Kloman
- "Grey Poupon". Kraftfoodservice.com. Retrieved 4 November 2013.
- "The Best-Selling Condiments in the U.S.: No. 11 Best-Selling Condiment: Grey Poupon Mustard". Bloomberg Businessweek. Retrieved 2013-11-05.
- Roger M. Grace. "Gulden's Is Oldest Nationally Sold Prepared Mustard-Not French's". Metnews.com. Retrieved 2013-11-05.
- "Dijon Mustard - Cook's Illustrated". www.cooksillustrated.com. Retrieved 2015-12-22.
- "2010 Best of Cleveland: Food". Cleveland Magazine. October 2010.
- "The History of Taylors". Taylors Products. Retrieved 7 January 2018.
- "Williams-Sonoma Beer Mustard". Williams-Sonoma. Retrieved 4 November 2013.
- "Creole Mustard". Zatarains.com. Retrieved 4 November 2013.