Marks & Spencer plc (known also as M&S, Your M&S and sometimes colloquially as Marks and Sparks, Marks or Marks's) is a British retailer, with several branches outside of the UK. It is one of the most widely recognised chain stores in the UK and is the largest clothing retailer in the UK, as well as being a multi-billion pound food retailer. Most of its shops sell both of these categories. It also has a third line of business selling homewares such as bedlinen, but this is far smaller than the other two.

The origin of Marks and Spencer was a chain of "Penny Bazaars", founded in 1884 by a Russian-born Polish-Jewish immigrant, Michael Marks in Leeds with a loan of £5 from Issac Dewhirst, a wholesaler. The site of the first stall is marked with a green and gold commemorative clock in Leeds Kirkgate Market. One of the original Penny Bazaars - in the Grainger Market, Newcastle upon Tyne - remains open to this day, and is now the smallest Marks & Spencer store in operation. Marks' first full store was opened in 1894 at Stretford Road, Hulme, in Manchester. Marks entered into a partnership with Thomas Spencer who was working as Dewhirst cashier. Dewhirst went into manufacturing and remains the biggest supplier to M&S. The official first Marks and Spencer store opened in 1904. Then when founders Michael Marks and Thomas Spencer passed away, the title of Chairman went to Marks' son Simon Marks. Simon Marks started to work with his friend Israel Sieff and thanks to their joint efforts, Marks and Spencer grew to become a household name. Marks and Spencer became a Limited Company after adopting the revolutionary policy of buying directly from manufacturers. In 1926 the company then started selling textiles and in 1928 the St Michael Trade Mark was registered. In 1930 M&S opened a flagship store at Marble Arch, London. Then Café Bars were introduced in many stores. These provided cheap, hygienic and nutritious mass catering. This was a valuable resource during the war, making efficient use of scarce food. In 1931, a food department was introduced selling produce and canned goods. By 1956, all goods were sold under the St Michael label. In 1964, Simon Marks died after 56 years' service to the Company, and Israel Sieff took over as Chairman. In 1974, Asian food was introduced into the stores. M&S opened up stores in continental Europe in 1975, then four years later in The Republic of Ireland. In 1988, the company acquired Brooks Brothers, an American clothing company and Kings Super Markets, a US food chain. By 1999, Online Shopping was brought in, and the company grew with new sales of fashion clothing.

M&S made its reputation in the 20th century on a policy of only selling British-made goods. It entered into long term relationships with British manufacturers, and sold the goods under the "St Michael" brand (trademark registered in 1928), which was used for both clothes and food. It also accepted the return of unwanted goods, giving a full cash refund if the receipt was shown, no matter how long ago the product was purchased. However, it has now adopted a 90-day returns policy. The company put its main emphasis on quality, but for most of its history, it also had a reputation for offering fair value for money. When this reputation began to waver, it encountered serious difficulties. Arguably, M&S has historically been an iconic retailer of 'British Quality Goods'. Its business model required suppliers to commit to long term contracts solely with M&S. This approach often led to over-reliance by manufacturers on the portion of trade they did with M&S. Accordingly, when the M&S fashion buyers changed suppliers on some aspects of the company's retail clothing offering, manufacturers were left dangerously exposed — many became insolvent. This has resulted in a change of climate, and no longer is a contract to supply M&S held up as the panacea it once was.

Unlike most of its rivals M&S resisted the lure of television advertising when ITV was launched in 1955, preferring to rely on its reputation to draw in customers. It was not until the mid-1990s that the first TV commercials for M&S clothing were broadcast.

"M&S Christmas Food" featuring the voice of Dervla Kirwan

"M&S Organic Food" featuring the voice of Dervla Kirwan

"From M&S With Love" a James Bond pastiche featuring Twiggy, Erin O'Connor, Laura Bailey, Noemie Lenoir, Lizzy Jagger and Dame Shirley Bassey performing 'Get the Party Started' (originally by Pink)