The leading professional body for accrediting archaeologists. They have a Special Interest Group for all professional members who are engaged in Graphics of any kind.
If you're starting out or looking for specialist information on a specific aspect of archaeological illustration. Here are some recommendations and papers
If you are looking for work in archaeology, this is the place to start. Not just for the jobs listings but the wealth of information of practical skills (including the BAJR Guide series)
IAI is the representative body for all the archaeologists of Ireland. It is an organisation with a Memorandum of Understanding with CIfA.
Designed for the amateur rather than professional archaeologist but a huge wealth of location specific information
The overarching European Society for archaeology bringing together amateur and professional as well as academic, public and private enterprise.