How do you greet someone who is CBE?

When greeting someone who is a Commander of the Order of the British Empire (CBE), it’s polite to address them as "Sir" or "Madam" followed by their last name, depending on whether they are male or female. You can say, "Good morning, Sir [Last Name]" or "Good morning, Madam [Last Name]." If you are on familiar terms, a simple "Hello" or "Hi" may also be appropriate, but it’s best to err on the side of formality initially.