Sr, Sr. or sr as an abbreviation may refer to:
- Senior, a suffix to a person's name, usually male
- Serbian language (ISO 639 alpha-2)
- Sister, a prefix to a religious sister's name
- Strontium, the 38th element on the periodic table
- The symbol of Steradian, metric (SI) unit of solid angle
- The Sunderland postcode area in the UK
- Suriname, a country in South America
- .sr, Suriname's Internet top-level domain