General:
* Attorney
* Counselor
* Advocate
* Legal professional
* Jurist
More specific:
* Barrister (UK, specializing in court appearances)
* Solicitor (UK, providing legal advice)
* Public defender (representing indigent defendants)
* Pro se (representing oneself in court)
Informal:
* Legal eagle
* Ambulance chaser (negative connotation)
The best synonym to use will depend on the specific context of your writing.