Labeling a Continuous Reference Grid per cell

[Zelong]

So per the image I have a Continous Reference Grid in my layout.  The user of the map would like to have labels for each Grid Cell, so a label for A1, B1, etc.

I am not seeing how to do that other than manually making the labels which I would rather not do.

Is there an automated way to do this?

Thank you

[RichardHowe]

I would suggest converting the grid to a feature as here

Labelling the newly created feature and making the grid symbology invisible, if you;re happy with the grid as it is in your layout

[Zelong]

So pro is saying that you cannot convert a Reference Grid to a feature layer on to a graphic

[JesseWickizer]

Since the Convert Grids to Features doesn't work with reference grids, a good method would be the Grid Index Features geoprocessing tool.

In that tool, check on Use Page Unit and Scale, set the Polygon Width and Polygon Height to match the size of each reference grid square, and the Number of Rows and Columns to match the reference grid. 

To set the Polygon Grid Origin Coordinate, if you don't already have a feature that matches your extent exactly you could add a graticule and use the Convert Grids to Features tool to output the neatline to a feature class - then use that neatline feature class as the Input Features parameter of the Grid Index Features tool.