The abbreviation HSR may stand for:
- High school reunion
- High-speed rail
- Haliburton Scout Reserve, a Scouts Canada camp located near Haliburton, Ontario
- Hamilton Street Railway
- Hart-Scott-Rodino Antitrust Improvements Act
- Health Services Research
- Homogeneously staining region
- Hierarchical state routing, a routing protocol for ad hoc networks
- Homestar Runner, an Internet cartoon
- Horseshoe Scout Reservation
- Hungarian Soviet Republic
- Henson Scout Reservation, a Boy Scout Reservation on the Eastern Shore of Maryland
- Hochschule für Technik Rapperswil, a university of applied sciences in St. Gallen, Switzerland
- Human subject research, scientific testing on humans
- Hidden surface removal
- High-availability Seamless Redundancy, a network protocol for fault-tolerance in Ethernet
- Historical Social Research, an academic journal of quantitative social science history
- Human Sexual Response (band)