The Suffolk County National Bank of Riverhead, Port Jefferson Branch Basic Info Reviews Routing Numbers Map & Direction Name: The Suffolk County National Bank of Riverhead, Port Jefferson Branch Main Office: No Service: Full Service Brick and Mortar Office Location: 228 East Main Street Port Jefferson, New York 11777 Suffolk County View other branches Phone: 631-473-7700 Please enable JavaScript to view the comments powered by Disqus. From: To: