This method will introduce the Find and Replace feature to extract the last names from all full names, and then you can sort full names by the last name easily. Please do as follows:

1. Copy the full name column, and paste it beside the full name column, says Column B.

2. Keep selecting the pasted column, and press the Ctrl + H keys simultaneously to open the Find and Replace dialog box.
Note: You can also open this dialog box by clicking Home > Find & Select > Replace.

3. In the opening Find and Replace dialog box, please type a space into the Find What: box, type the @ into the Replace with: box, and then click the Replace All button. See screenshot:

And then a dialog box will pop up and show you how many replacements have been made, just click the OK button to close it.

4. Still select the new column, and in the Find and Replace dialog box, enter the *@ in the Find what: box, enter nothing in the Replace with: box, and then click Replace All button.

And then a dialog box will pop up and show you how many replacements have been made, just click the OK button to close it.

5. Keep selecting the new column, and click Data > Sort A to Z or Sort Z to A, and then in the Sort warning dialog box please check the Expand the selection option, and click the Sort button. See screenshot:

So far the full name column has been sorted by the extracted last names. If necessary, you can delete the new extracted last name column.

Easily sort by last name/word in cells in Excel

Kutools for Excel's Advanced Sort utility supports sorting data by many flexible scenario/methods, such as sort by text length, sort by frequency, sort by last name, etc.

If we can extracting the last name from each full name, and then it’s easy to sort the list of full names by the last names. This method will introduce Kutools for Excel’s Split Names utility to extract the last names firstly, and then sort by last name.

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1. Select the full name column without column header, and click Kutools > Text > Split Names. And then in the opening Split Names dialog box, please check the Last name option only, and click the Ok button. See screenshot:

2. In the second Split Names dialog box, please specified the first cell of destination column beside original full name column, and click the OK button.
And then all last names are extracted from full names and placed beside original full name column. See screenshot:

3. Select the new last name column, and click Data > Sort A to Z or Sort Z to A, and then in the Sort warning dialog box please check the Expand the selection option, and click the Sort button. See screenshot:

And now the full name column is sorted by the last names. If necessary, please delete the new created last name column as you need.

Actually, we can reverse the full name cell and place the last name at the beginning of cell by the Reverse Text Order utility of Kutools for Excel, therefore it will be quite easy to sort by last names.

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1. Select the full name column without the column header, and click Kutools > Text > Reverse Text Order. See left screenshot:

2. In the opening Reverse Text dialog box, please check the Space option, and click the Ok button. See screenshot:

3. Select the full name column, and then click Data > Sort A to Z or Sort Z to A. So far the full name column has been sorted by the last name already. But we need to restore the normal full name order.

4. Repeat Step 1 and Step 2 to restore normal full name order.
Please Select the full name column without the column header, and click Kutools > Text > Reverse Text Order. And then check the Space option and click the Ok button in the Reverse Text dialog box. See screenshot:

Using Text to Column function or Find and Replace function to sort name by last name are no easier than applying Advanced Sort feature of Kutools for Excel.

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1. Select the full name column you want to sort by last name, and click Kutools Plus > Advanced Sort to enable this feature.

2. In the pop-up Advanced Sort dialog, select the column you want to sort, choose Last name from Sort On drop down list, specified the sort order from the Order drop down list, and click the Ok button. See screenshot:

So far the full name column has been sorted by last name at once.