International Distributions Services plc (formerly Royal Mail plc), trading as Royal Mail, Parcelforce and GLS, is a British multinational postal service and courier company, originally established in 1516 as a government department. The company's subsidiary Royal Mail Group Limited operates the brands Royal Mail (letters and parcels) and Parcelforce Worldwide (parcels). GLS Group, an international logistics company, is a wholly owned subsidiary of Royal Mail Group. The group used the name Consignia for a brief period in the early 2000s and Royal Mail until October 2022.

The company provides mail collection and delivery services throughout the UK. Letters and parcels are deposited in post or parcel boxes, or are collected in bulk from businesses and transported to Royal Mail sorting offices. Royal Mail owns and maintains the UK's distinctive red pillar boxes, first introduced in 1852 (12 years after the first postage stamp, Penny Black), and other post boxes, many of which bear the royal cypher of the reigning monarch at the date of manufacture. Deliveries are made at least once every day except Sundays and bank holidays at uniform charges for all UK destinations. Royal Mail generally aims to make first class deliveries the next business day throughout the nation.

For most of its history, the Royal Mail was a public service, operating as a government department or public corporation. Following the Postal Services Act 2011, a majority of the shares in Royal Mail were floated on the London Stock Exchange in 2013. The UK government initially retained a 30% stake in Royal Mail,[8] but sold its remaining shares in 2015, ending 499 years of state ownership. It is a constituent of the FTSE 250 Index.