The Sony Ericsson Xperia X8 is a mid-range 3G Android smartphone developed by Sony Ericsson in the Xperia series released in Q4 2010. It was sold in many countries worldwide, including the United States on AT&T Mobility and low-end pay-monthly contracts in the UK. It originally shipped running Android 1.6 but was upgraded in early 2011 to Android 2.1.

Xperia is a series of and the sole brand name of smartphones marketed by Sony. It also includes various related mobile hardware such as tablets as well as software. Xperia was originally developed by Sony Ericsson before becoming Sony Mobile as a result of the mobile phone manufacturer being taken over and solely owned by Sony in 2012; it has been under Sony Corporation since 2021 following Sony Mobile's merger. The name Xperia is derived from the word "experience", and was first used in the Xperia X1 tagline of "I Xperia the best".