Yes, you can add a circle around a letter in Excel. Here's how:

1. First, select the cell containing the letter you want to add a circle around.
2. Next, go to the Insert tab in the Excel ribbon.
3. Click on the Shapes button, which is located in the Illustrations group.
4. Choose the circle shape from the list of shapes.
5. Click and drag the cursor on the cell to draw the circle around the letter.
6. You can adjust the size and position of the circle by clicking and dragging the edges or corners of the shape.
7. To change the color or style of the circle, right-click on the shape and select Format Shape from the dropdown menu.
8. In the Format Shape pane, you can choose a different color, add a border, or adjust other formatting options.
9. Once you're happy with the circle, you can move or resize the cell as needed to fit it into your worksheet.

That's it! You now have a circle around your letter in Excel.