Dogecoin (/ˈdoʊ(d)ʒkɔɪn/ DOHJ-koyn or DOHZH-koyn, Abbreviation: DOGE; sign: Ð) is a cryptocurrency created by software engineers Billy Markus and Jackson Palmer, who decided to create a payment system as a joke, making fun of the wild speculation in cryptocurrencies at the time. It is considered both the first "meme coin", and more specifically the first "dog coin". Despite its satirical nature, some consider it a legitimate investment prospect. Dogecoin features the face of Kabosu from the "doge" meme as its logo and namesake. It was introduced on December 6, 2013, and quickly developed its own online community, reaching a peak market capitalization of over US$85 billion on May 5, 2021. As of 2021, it is the sleeve sponsor of Watford Football Club.

Dogecoin.com promotes the currency as the "fun and friendly Internet currency", referring to its origins as a "joke". Software engineers Markus and Palmer launched the satirical cryptocurrency as a way to make fun of Bitcoin and the many other cryptocurrencies boasting grand plans to take over the world. Dogecoin quickly gained traction, particularly on social platforms like Reddit. Within two weeks of launch, it had established a dedicated blog and forum and its market value reached $8 million, once jumping to become the seventh largest electronic currency in the world.

Originally formed as a joke, Dogecoin was created by IBM software engineer Billy Markus and Adobe software engineer Jackson Palmer. They wanted to create a peer-to-peer digital currency that could reach a broader demographic than Bitcoin. In addition, they wanted to distance it from the controversial history of other coins. Dogecoin was officially launched on December 6, 2013, and within the first 30 days, there were over 1 million visitors to Dogecoin.com.

Palmer is credited with making the idea a reality. At the time, he was a member of the Adobe marketing department in Sydney, Australia, while Markus was a senior software engineer at IBM in Portland, Oregon. Palmer had purchased the domain Dogecoin.com and added a splash screen, which featured the coin's logo and scattered Comic Sans text. Markus reached out to Palmer after seeing the site, and started efforts to develop the currency. Markus designed Dogecoin's protocol based on existing cryptocurrencies Luckycoin and Litecoin, which use scrypt technology in their proof-of-work algorithm. The use of scrypt means that miners cannot use SHA-256 bitcoin mining equipment, and instead must use dedicated field-programmable gate array and application-specific integrated circuit devices for mining which are known to be more complex to produce.

On December 19, 2013, Dogecoin jumped nearly 300% in value in 72 hours, rising from $0.00026 to $0.00095, with a volume of billions of Dogecoins traded per day. This growth occurred during a time when Bitcoin and many other cryptocurrencies were reeling from China's decision to forbid Chinese banks from investing in the Bitcoin economy. Three days later, Dogecoin experienced its first major crash when its price dropped by 80% due to this event and to large mining pools exploiting the small amount of computing power required at the time to mine Dogecoin.

On December 25, 2013, the first major theft of Dogecoin occurred when millions of coins were stolen during a hack on the online cryptocurrency wallet platform Dogewallet. According to the platform's management, the hacker, having gained access to the platform, redirected all transactions to a single wallet address. This hacking incident spiked tweets about Dogecoin, making it the most mentioned altcoin on Twitter at the time, although it was in reference to a negative event. To help those who lost funds on Dogewallet after its breach, the Dogecoin community started an initiative named "SaveDogemas" to help donate coins to those who had them stolen. Approximately one month later, enough money was donated to cover all of the coins that were stolen.

In January 2014, the trading volume of Dogecoin briefly surpassed that of all other cryptocurrencies combined. However, its market capitalization remained substantially behind that of Bitcoin. Initially, Dogecoin featured a randomized reward that is received for each mining block. However, in March 2014, this behaviour was updated to a static block reward. Co-founder Jackson Palmer left the cryptocurrency community in 2015 and has no plans to return, having come to the belief that cryptocurrency, originally conceived as a libertarian alternative to money, is fundamentally exploitative and built to enrich its top proponents. His co-founder, Billy Markus, agreed that Palmer's position was generally valid.

During the 2017 to early 2018 cryptocurrency bubble, Dogecoin briefly reached a peak of $0.017 on January 7, 2018, putting its total market capitalization near $2 billion.