Telegram (also known as Telegram Messenger) is a cloud-based, cross-platform social media and instant messaging (IM) service. It launched for iOS on 14 August 2013 and Android on 20 October 2013. It allows users to exchange messages, share media and files, and hold private and group voice or video calls as well as public livestreams. It is available for Android, iOS, Windows, macOS, Linux, and web browsers. Telegram offers end-to-end encryption in voice and video calls, and optionally in private chats if both participants use a mobile device.

Telegram also has social networking features, allowing users to post stories, create large public groups with up to 200,000 members, or share one-way updates to unlimited audiences in so-called channels.

Telegram was founded in 2013 by Pavel Durov and Nikolai Durov. Its servers are distributed worldwide with several data centers, while the headquarters are in Dubai, United Arab Emirates. It was the most downloaded app worldwide in January 2021, with 1 billion downloads globally as of late August 2021. As of 2024^[update], registration to Telegram requires either a phone number and a smartphone or one of a limited number of non-fungible tokens (NFTs) issued in December 2022.

As of March 2025,^[update] Telegram has more than 1 billion monthly active users, with India as the country with the most users.

Telegram was launched in 2013 by the brothers Nikolai and Pavel Durov. Previously, the pair founded the Russian social network VK, which they left in 2014, saying it had been taken over by the government. Pavel sold his remaining stake in VK and left Russia after resisting government pressure. Nikolai created the MTProto protocol that is the basis for the messenger, while Pavel provided financial support and infrastructure through his Digital Fortress fund. Telegram Messenger states that its end goal is not to bring profit, but it is not structured as a non-profit organization.

Telegram is registered as a company in the British Virgin Islands and as an LLC in Dubai. It does not disclose where it rents offices or which legal entities it uses to rent them, citing the need to "shelter the team from unnecessary influence" and protect users from governmental data requests. After Pavel Durov left Russia in 2014, he was said to be moving from country to country with a small group of computer programmers consisting of 15 core members.

While a former employee of VK said that Telegram had employees in Saint Petersburg, Pavel said the Telegram team made Berlin, Germany, its headquarters in 2014, but failed to obtain German residence permits for everyone on the team and moved to other jurisdictions in early 2015. Since 2017, the company has been based in Dubai. Its data centers are spread across a complex corporate structure of shell companies in various jurisdictions to avoid compliance with government subpoenas. The company says this is done "to protect the data that is not covered by end-to-end encryption". Telegram's FAQ page says it does not process any requests related to illegal content in chats and group chats, and that "to this day, we have disclosed 0 bytes of user messages to third parties, including governments". However, according to Pavel, Telegram has disclosed data for 203 legal requests from the Brazilian government from Q1 to Q3 of 2024, and a total of 6,992 legal requests from India, its largest market, during the same period. Users can check how many legal requests from their country have been processed by Telegram using the official transparency bot.

In October 2013, Telegram announced that it had 100,000 daily active users.