Open the Excel workbook
Go to the View tab
Click Unhide
Select the hidden worksheet
Click OK
If the Unhide option is unavailable, right-click any sheet tab
Click Unhide
Select the worksheet
Click OK
If the workbook structure is protected, go to Review
Click Unprotect Workbook
Enter the password if prompted
Repeat the Unhide steps
If the sheet is hidden with VBA, open the Visual Basic Editor
Press Alt + F11
In the Project Explorer, select the hidden sheet
In the Properties window, set Visible to xlSheetVisible
Close the Visual Basic Editor
Save the workbook