Yes...
An ambassador is addressed as His Excellency or Her Excellency, unless they have a royal title. In the case of a royal title, it can be the ambassador who determines their preferred form of address.
If the Ambassador is currently active in the Diplomatic Service, it would be Mr. Ambassador or Madame [ Mme.] Ambassador.
When addressing an ambassador in person, it's customary to use their official title, such as "Your Excellency." You can follow this with their last name, for example, "Your Excellency, Ambassador Smith." If you are unsure of their title, "Ambassador" is an appropriate and respectful alternative. Always maintain a polite and formal demeanor during the interaction.
His/Her Excellency
Your Excellency.
(His Excellency) Simon Featherstone
His Excellency Vinod Kumar.
His Excellency, Mr Vinay Sheel Oberoi
The highest office in a Consulate is a Consul, the highest office in a Consulate-General is a Consul General, and the highest office in an Embassy is an Ambassador. You would address the letter as: The Honorable John Smith, Consul Consulate of "conventional long form of whatever country" Street address City, State, zip In the letter however, the salutation would simply be Dear Mr., Mrs., Miss, or Ms., the same goes for a Consul General A foreign Ambassador would be: His (or Her) Excellency John Smith Ambassador of "conventional long form of whatever country" Street address City, State, zip The salutation for an ambassador would be either Excellency, or Dear Mr. (or Madam) Ambassador
On the Envelope His/Her Excellency Mr./Ms./Dr./Rev. [name] Ambassador (or High Commissioner) of [country in full] In letter Dear Mr/Mrs Ambassador
Address the Governor General or his or her spouse as "Excellency" or "Your Excellency" first, then as "Sir" or "Madame" as is gender appropriate thereafter.
Her Excellency