Mount, who took on roles at lovethatwine.com and Wine Intelligence after leaving her job at Somerfield earlier this year, has joined the Bath-based company as non-executive director.
Commenting on the appointment, Great Western Wine managing director Philip Addis said he hoped she would help the company evolve from regional wholesaler to national distributor.
He said: "Her background in buying and marketing will be a huge asset to us in developing our key brands in the important target markets of the London on-trade and niche independents, and she completes what is now a strong and well-balanced board who can help to manage our expansion."
Her appointment coincides with that of Ian Barker, who also worked at Somerfield and who joins the company as operations director. On the board, they will sit alongside non-executive chairman Simon Wood, financial director Tim Henderson-Ross and sales director Joel Lauga.
Mount said she was looking forward to working with a "dynamic" company based in the south west. She said: "Great Western Wine has a fantastic portfolio of agency and exclusive wines, and represents some truly great estates and individual growers."