IHS may refer to: Religious Christogram IHS or ΙΗΣ, a monogram symbolizing Jesus Christ In hoc signo, used by Roman emperor Constantine the Great Organizations Indian Health Service, an operating division of the US Department of Health and Human Services Dictaphone company division for healthcare dictating applications IHS Markit, a data publishing company (Information Handling Services) that originated in 1959, and has since merged with Markit. Institutes Institute for Housing and Urban Development Studies, an international institute Institute for Humane Studies, a US educational organization Institute for Humanist Studies, a think tank based in Washington, DC Societies Indiana Historical Society, a historical society in the US International Headache Society, organisation for professionals helping people affected by headache International Horn Society, organization dedicated to horn-players Ipswich Historical Society, in Ipswich, Massachusetts, US Schools Independence High School (Arizona), US Irondequoit High School, Irondequoit, New York, US Issaquah High School, Issaquah, Washington, US The Indian High School, Dubai, United Arab Emirates Interlake High School, Bellevue, Washington, US Ithaca High School, Ithaca, New York, US Technology Intensity, hue, saturation, in the HSL color space IBM HTTP Server, a web server Integrated Heat Spreader, a heat spreader that serves as an interface between a chip and a heat sink Other uses Integrated Household Survey, a survey comprising multiple surveys in the UK Ironclads: High Seas, a naval simulator computer game