The Sony Ericsson Xperia ray (ST18i) is an Android smartphone from Sony Ericsson. It was unveiled on 22 June 2011 in Singapore during CommunicAsia 2011. It was announced that the Xperia ray would be released globally in select countries from Q3 2011.

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".