Datagaps ETL Validator
ETL and data pipeline testing tool, part of the Datagaps DataOps Suite
Faker
Python package that generates fake data
Faker (JavaScript)
Fake but realistic data for testing, in the browser and Node.js
Datafaker
Fake data generator for the JVM
Bogus
Fake data generator for C#, F# and VB.NET
Instancio
Automatically populated objects for Java unit tests