Which company produces the OnePlus smartphone series?

The company that produces the OnePlus smartphone series is OnePlus.

OnePlus Technology (Shenzhen) Co., Ltd., commonly known simply as OnePlus, is a Chinese consumer-electronics company headquartered in Shenzhen. Pete Lau and Carl Pei founded the company in December 2013 with the goal of offering high-end smartphones at lower prices than many competing flagship devices.

The company’s first phone, the OnePlus One, launched in 2014 and became known for strong specifications, an unusually low price, and an invitation-based purchasing system. It originally ran Cyanogen OS, an Android-based operating system. Later OnePlus phones used the company’s OxygenOS software in international markets.

OnePlus is backed by Oppo and shares parts of Oppo’s manufacturing and supply-chain infrastructure, which can cause confusion about the brand’s corporate identity. However, Oppo is not one of the answer choices here, and the smartphone series itself is the OnePlus line produced and marketed under the OnePlus brand. Google, Huawei, and Xiaomi are separate smartphone companies.