The entries in a Grapher legend are displayed in the same order as their associated plots in the Object Manager by default.  To change the legend entry order in Grapher v15 and newer, complete the steps below:

1. Select the legend. 
2. In the Property Manager, click the Entries tab. 
3. In the Individual Entries section, select the plot of interest in the Entry field.
4. Expand Entry order and use the options listed to edit the order. 
   

To change the legend entry order in Grapher v14, complete the steps below:

1. Select the legend. 
2. In the Property Manager, click the Legend tab. 
3. Next to Entries click the Edit button. 
4. In the Legend Entries dialog, select the layer you would like to reorder, then toggle the up or down arrow on the right side of the dialog.
   
5. Click Apply to see changes and OK to exit the dialog. 

Updated March, 2020