See solution in other versions of Excel:
Before trying the following solution, you might want to make sure that you don't have any frozen panes that you need to unfreeze:
Learn how to unfreeze panes in Excel:
Question: How do I unhide column A in a sheet in Microsoft Excel 2010?
Answer: Select the Home tab from the toolbar at the top of the screen. In the Editing group, click on the Find button and select "Go To" from the popup menu.
When the GoTo window appears, enter A1 in the Reference field and click on the OK button.
Select the Home tab from the toolbar at the top of the screen. Select Cells > Format > Hide & Unhide > Unhide Columns.
Now you should be able to see column A in your Excel spreadsheet.