How to add a drop down list in a Excel spreadsheet in the title/header columns?

For header cells, the drop-down is created the same way as any other cell: select the header cell, then go to Data > Data Validation > Allow: List.

The key point is the Source must be a valid single range reference or a typed comma-separated list.

Use one of these supported approaches:

1. Put the list items in a single column or row on a worksheet.
2. Select the header cell where the drop-down should appear.
3. Go to Data > Data Validation.
4. On Settings, set Allow to List.
5. In Source, select only the cells that contain the list items.
   • Do not include the header cell of that source list.
   • The source must be one continuous range.
6. Make sure In-cell dropdown is checked.
7. Select OK.

If the source list is in an Excel table, the drop-down updates automatically when items are added or removed from that table.

If the list is small, the entries can also be typed directly into Source separated by commas, for example: High,Medium,Low

If Excel says the reference cannot be used in a data validation formula, common fixes from the supported setup are:

• Use a single continuous row or column as the source.
• Exclude the source header cell.
• If the worksheet is protected or shared and Data Validation is unavailable, unlock the needed area or stop sharing first.

If the goal is a more interactive control in a header area rather than standard data validation, a combo box can also be added from Developer > Insert and linked to a cell, but for most header drop-downs, Data Validation is the simpler option.

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• Add a list box or combo box to a worksheet in Excel