Use LSEG Workspace (formerly Refinitiv). From a company profile, select Price & Charts --> Short Interest or use the search bar at the top of the page to type the ticker symbol followed by SI (for short interest).

Use Compustat, available in WRDS (see access details):

• Select North America - Supplemental Short Interest File.
• Includes mid-month and end-of-month positions.
• Population coverage includes the New York Stock Exchange, American Stock Exchange, and NASDAQ.

Use Bloomberg (see access details).

• Enter the company ticker symbol, hit the yellow <EQUITY> key, type SI, then hit <GO> (e.g.: IBM <EQUITY> SI <GO>).
• The screen will initially load with a graph. You can <Page Down> to find a data table.

Global Financial Data offers summary NYSE Short Interest Ratio and NYSE Short Interest Shares data to chart or download. Search for short interest. Data is available from 1931 through November 2021. 

FINRA has daily short sale volume files from August 2009 to present. 

You can find the last year of short interest data by ticker on NasdaqTrader.com.