SWI may refer to:

Places Switzerland (UNDP country code; not the ISO 3166-1 code, which is CHE) Swindon railway station (National Rail code SWI), serving Swindon, Wiltshire, United Kingdom Sherman Municipal Airport, Texas, United States, with the FAA LID of SWI

Science and technology SWI-Prolog, a free implementation of the programming language Prolog Susceptibility weighted imaging, in magnetic resonance imaging (MRI) used in medical contexts Software interrupt, an interrupt routine in a computer operating system SWI, an assembler mnemonic to perform a software interrupt on the ARM microprocessor family Standard Work Instruction, codification of standard work in manufacturing Szilagyi Waterspout Index

Other uses Swissinfo, a service of the Swiss Broadcasting Corporation Structured Word Inquiry, a pedagogical technique involving the scientific investigation of the spelling of words Scottish Women's Institutes, a registered charity in Scotland