One Plus Technology (Shenzhen) Co., Ltd., commonly referred to as OnePlus, is a Chinese smartphone manufacturer based in Shenzhen, Guangdong. It was founded by Pete Lau (CEO) and Carl Pei (Director) in December 2013. The company officially serves 34 countries and regions around the world as of July 2018. They have released numerous phones, amongst other products. It is currently majority owned by Oppo as its only shareholder, which is a subsidiary of BBK Electronics along with Vivo and Realme. However, both OnePlus and Oppo denies OnePlus is a subsidiary and maintain they are independent companies, although OnePlus confirmed it uses Oppo's manufacturing line and shares part of the supply chain resources with Oppo.

The company's main goal was to design a smartphone that would balance high-end quality with a lower price than other phones in its class, believing that users would "Never Settle" for the lower-quality devices produced by other companies. Lau explained that "we will never be different just for the sake of being different. Everything done has to improve the actual user experience in day-to-day use." He also showed aspirations of being the "Muji of the tech industry", emphasizing its focus on high-quality products with simplistic, user-friendly designs. Continuing Lau's association with the platform from the Oppo N1, OnePlus entered into an exclusive licensing agreement with Cyanogen Inc. to base its products' Android distribution upon a variant of the popular custom ROM CyanogenMod and use its trademarks outside of China.

The company unveiled its first device, the OnePlus One, on 23 April 2014 which was intended to capture market from the Google Nexus series. In December 2014, alongside the release of the OnePlus One in India exclusively through Amazon, OnePlus also announced plans to establish a presence in the country, with plans to open 25 official walk-in service centre across India.

In April 2014, OnePlus hired Han Han to help market its products in mainland China.

On 9 March 2014, the company expanded its operations to the European Union.

On 16 December 2014, The Supreme Court of India and Delhi High Court banned the import and sale of OnePlus One phones following a lawsuit by Micromax alleging it has exclusivity for shipping phones with Cyanogen OS software in India. On 21 December 2014, the ban was lifted. The device continues to be shipped with Cyanogen OS; however, a customized version of Android specially designed by OnePlus and named OxygenOS has been released, allowing later OnePlus devices to be sold in India.

OnePlus made its products available in Southeast Asia for the first time, partnering with Lazada Indonesia on 23 January 2015 and was expected to expand during that year throughout the region. In June 2016, OnePlus decided to pull out of the Indonesian market due to local regulations for imported 4G smartphones restricting sales of the OnePlus 2.

At the launch event of the OnePlus 6 on 17 May 2018, OnePlus announced it would be opening five new OnePlus Experience stores in India, as well as 10 new service centre.

According to market research firm Counterpoint Research, OnePlus topped the Indian premium smartphone market last year with a 33 percent share, beating Samsung Electronics with 26 percent. In the IDC survey, OnePlus ranked third in India's market with more than $500 in the first quarter of this year after Apple and Samsung Electronics. And it ranked second after China's Vivo in the 300-500-dollar market.