- Cinco Ranch High School – 23440 Cinco Ranch Blvd. – 281-237-7000
- Freeman High School – (newer campus; Katy ISD secondary campus)
- Jordan High School – 27500 Fulshear Bend Dr. – 281-396-6000
- Katy High School – 6331 Highway Blvd. – 281-237-6700
- Legacy Virtual High School – district virtual high school
- Mayde Creek High School – 19202 Groschke Rd. – 281-237-3000
- Morton Ranch High School – 21000 Franz Rd. – 281-237-7800
- Paetow High School – 23111 Stockdick School Rd. – 281-234-4900
- Seven Lakes High School – 9251 S. Fry Rd. – 281-237-2800
- Taylor High School – 20700 Kingsland Blvd. – 281-237-3100
- Tompkins High School – 4400 Falcon Landing Blvd. – 281-234-1000
Other Katy ISD Secondary / Alternative Programs
- Raines Academy – 1732 Katyland Dr.
- Miller Career & Technology Center – 1734 Katyland Dr.
- Opportunity Awareness Center – 1732 Katyland Dr.
- Robert R. Shaw Center for STEAM – 1730 Katyland Dr.