Formal:
* Reference provider: This is a neutral and formal term.
* Recommender: This implies the person is actively recommending someone.
* Referee: This is commonly used in academic or professional settings.
Informal:
* Someone who gives a reference: This is the most straightforward option.
* The person who wrote the reference: This clarifies who provided the reference.
You can also use descriptive phrases like:
* A former employer who provided a reference
* A professor who wrote a letter of recommendation
The best term to use will depend on the specific situation and your desired level of formality.