ISTAT may refer to:

• International Society of Transport Aircraft Trading
• National Institute of Statistics (Italy) (Istituto Nazionale di Statistica)
• i-STAT, a blood analyzer made by Abbott Laboratories

• Halmerend (ward)
• Hal M. Hornburg
• Halmich
• Halmidi
• Halmidi inscription
• Hal Miller
• Halmir
• Hal Mitchel
• Hal Mitchell
• Hal Mohr
• Hal Mooney
• Hal Morris
• Halmos box
• Halmos College of Natural Sciences and Oceanography
• Halmos symbol
• Halmstad Airport
• Halmstad Castle
• Halmstad GK
• Halmstad (Niklas angående Niklas)
• Halmstads pärlor
• Halmstad, Sweden
• Halmstad University
• Hal Mumme
• Hal Munson
• Hal Murphy