Harry D. Jacobs High School (commonly referred to as Jacobs or HDJ) is a public high school for students in grades 9 through 12 located in Algonquin, Illinois, a northwest suburb of Chicago, serving students from the west half of the Village of Algonquin and its surrounding areas, including Lake in the Hills, Gilberts, some of Sleepy Hollow, some of Carpentersville, and some of West Dundee.

The school is located in McHenry County but also draws students from Northern Kane County.

Harry D. Jacobs High School is part of Community Unit School District 300, and one of three high schools serving the district.

The school is a member of the Illinois High School Association, Fox Valley Conference.

[4][1] Jacobs High School offers the following programs: Athletics Activities Music Jacobs offers AP courses in the following subjects: Biology, Calculus AB, Calculus BC, Chemistry, Computer Science A, Computer Science Principles, English Language, English Literature, Environmental Science, Human Geography, Macroeconomics, Music Theory, Physics 1, Physics C, Precalculus, Psychology, Research, Seminar, Spanish Language, Spanish Literature, Statistics, Studio Art, US Government, and US History.