SOI

SOI may refer to:

Technology

• Silicon on Insulator
• Signal operating instructions
• Service-oriented infrastructure
• Start of injection
• Stages of involvement, FAA review for DO-178B Aircraft software development

Science

• Southern Oscillation Index
• Sphere of influence (astrodynamics), a term in astrodynamics

Misc

• Soi, a side street in Thailand
• Sociosexual Orientation Inventory
• School of Infantry
• Shadow of Infinity, a Yu-Gi-Oh! Trading Card Game set
• Sons of Iraq, auxiliary police forces in Iraq
• Severity of illness, medical classification
• Sphere of influence, a term in politics
• Survey of India
• State of Israel
• The Symphony Orchestra of India
• Stars on Ice, skating tour
• Share of investment, in marketing
• Sons of Intellect, a hip-hop group
• Supplier-owned inventory, in warehouse logistics