The 33-year-old departs by mutual consent having played almost 100 games over three seasons at the club.
Sports boss Danny Bloor said: “Dean has been a fantastic servant to Eastbourne Borough Football Club. After lengthy discussions, we mutually agreed a parting of ways and I certainly wish him and his family all the best for the future. He will be a big loss both on and off the pitch, and everyone at the club will certainly make sure he has a warm welcome should he come back to Priory Lane at any time.”