CODESYS is not available for Mac but there are a few alternatives that runs on macOS with similar functionality. The best Mac alternative is 4diac, which is both free and Open Source. If that doesn't suit you, our users have ranked nine alternatives to CODESYS and three of them are available for Mac so hopefully you can find a suitable replacement. Other interesting Mac alternatives to CODESYS are logi.CAD 3 - Engineering Toolkit (Paid) and LOGO! Soft Comfort (Paid).
The programming tool logi.CAD 3 is built on eclipse and its focus is on efficient and effective programming of controllers according to IEC 61131-3 for every kind of size - from Micro-Controllers to Multi-Core Industry PCs.
LOGO! Soft Comfort is software for programming simple Siemens LOGO! PLCs. Programming is done in one of two graphical programming languages - FBD (Function Block Diagram) or LAD (Ladder Diagram). Simulation and online monitoring is available.