Ethel M Chocolates is an American chocolate manufacturer and retailer, based in Henderson, Nevada. It was founded by Forrest Mars Sr. in 1981, and is named after his mother, Ethel Mars. The company produces preservative-free chocolates using her recipes. It has been owned by Mars Inc. since 1988.

Ethel M Chocolates was founded by Forrest Mars Sr., who previously oversaw Mars Inc., known for its candy products. Mars retired from the eponymous company in 1973, but soon grew bored. In 1979, he was planning a new candy venture named after his mother, Ethel Gale Mars (nee Kissack). Mars and his mother had moved to the Las Vegas Valley in 1975, and she lived there until her death in April 1980, at the age of 97.

The company's factory began operations in March 1981, in Henderson, Nevada, part of the Las Vegas Valley. Retail stores were established throughout the area, and eventually in other states. The chocolates are made without preservatives, using recipes created by Ethel Mars. Because the chocolates lack preservatives, they have a short shelf-life. As such, the tourist-driven Las Vegas Valley was deemed ideal for quick product sales. Henderson was also chosen because of its lack of pollution, as chocolate is susceptible to odors.

Ethel M quickly became popular for its liqueur-filled chocolates, which accounted for 5 of the 24 varieties offered at the time. The liqueur candies were sold only in Nevada, one of two states allowing large quantities of liquor in candy, the other being Kentucky. This was another factor for establishing the business in Nevada.

Within a few years, retail stores were opened in northern California. Ethel M soon had annual sales of $150 million, generated through 70 stores throughout the western United States. Ethel M was purchased by Mars Inc. in 1988, and Mars himself soon moved to Miami. By 1991, Ethel M had 50 stores across Arizona, California, and Nevada. Further states were excluded, due to the negative effects that long shipping times had on the chocolates. Ethel M had 500 workers as of 2003, and was among the largest manufacturing employers in Henderson. It had 15 retail outlets at that time, 13 of them in Nevada.

In 2005, Mars Inc. debuted a series of chocolate lounges in the Chicago area under the name Ethel's Chocolate Lounge. The concept capitalized on a growing trend of chocolate lounges around the U.S. This was accompanied by the launch of Ethel's Chocolates, a high-end line distinct from the more affordable Ethel M brand. These chocolates, also made in Henderson, were sold online and at Ethel's Chocolate Lounges. The first Nevada-based lounge was opened in 2006, at the Fashion Show Mall on the Las Vegas Strip. The Chicago lounges underperformed during the Great Recession, and were closed in 2009.

In 2017, Ethel M revived two chocolate bar varieties: Mars, which had been discontinued in 2002; and Forever Yours, discontinued in 1979.

Ethel M partnered with the Vegas Golden Knights hockey team in 2017, a deal which included featuring its chocolate at games. Ethel M, in celebration of its 40th anniversary, also sponsored NASCAR driver Kyle Busch and his No. 18 Toyota Camry race car in the 2021 Pennzoil 400 race in Las Vegas, and would do so again for the 2022 event.

As of 2024, Ethel M has nine retail locations throughout the Las Vegas Valley, and one at the Glendale Galleria in Glendale, California. The chocolates are also sold at select businesses around the U.S. and through the company's website.

The Ethel M Chocolates Factory is located at 2 Cactus Garden Drive in Henderson, and is a popular attraction. A portion of the factory interior is open to the public for free self-guided tours, with windows providing a view of the chocolate-making process. The facility also includes a retail store for the company's products, and a chocolate and wine-tasting room. As of 2011, the factory received 700,000 visitors a year.

As of 2016, the factory produces approximately 8 million pieces of chocolate annually. Various fillings are also produced on-site, including peanut butter, caramel, and various fruit-based creams. It is the sole production facility for Ethel M products. From 1996 to 2003, the factory also produced seasonal candies for other brands owned by Mars Inc., including Dove, Milky Way, and Snickers. In addition, it has served as a test kitchen for new Mars candies. Mars himself had an apartment above the factory, where he lived during the 1980s while overseeing the company. The apartment was later converted into office and work space.