Toad Data Modeler is not available for Mac but there are some alternatives that runs on macOS with similar functionality. The best Mac alternative is MySQL Workbench, which is both free and Open Source. If that doesn't suit you, our users have ranked more than 10 alternatives to Toad Data Modeler and five of them are available for Mac so hopefully you can find a suitable replacement. Other interesting Mac alternatives to Toad Data Modeler are pgModeler (Freemium, Open Source), SQL Developer Data Modeler (Free), Moon Modeler (Freemium) and DbDesigner.net (Paid).
MySQL Workbench is a unified visual tool for database architects, developers, and DBAs. MySQL Workbench provides data modeling, SQL development, and comprehensive administration tools for server configuration, user administration, and much more.
pgModeler is an open source tool for modeling databases that merges the classical concepts of entity-relationship diagrams with specific features that only PostgreSQL implements. Built over Qt framework, pgModeler can be compiled under Windows, Linux and macOS.
Oracle SQL Developer Data Modeler is a free graphical tool that simplifies data modeling tasks. Using Oracle SQL Developer Data Modeler users can create, browse and edit, logical, relational, physical, multi-dimensional, and data type models.