To create Drop Down list in Excel follow the below Simple steps,
First Create A Excel Sheet and enter the data that you have to add in Drop down list,
For more clarity see the below image,
Then select all column and then Right click on it and select Define Name,
Enter Any name in Text box and then click on OK button,
Then select any cell where you have to add Drop down box After it go to Data menu and click on Data Validation tab,
In allow box select List and then in source box enter your Define name,as we have already defined previous step.
Your Drop down List created as below.