To do Alt + H A L on Mac in Excel, download and install Accelerator Keys, then press Option, followed by H, A, L.
Command: Align Left
This is how to do Alt + H A L on Mac in Excel with Accelerator Keys, the native ribbon and alt key shortcut solution for Mac users who get more done with Excel.
Alt + H A L positions cell contents at the left edge of the cell. This is the default alignment for text and is best for labels and text data.