Wondering how tall your fence can be in Delaware? The rules do not just apply statewide many municipalities have their own rules and regulations. Lucky for us Delaware only has three counties and we will break down each county for you here:

KENT COUNTY

•  For a fence to be considered legal it should be at least 4' in height. 
• You may install a residential fence up to 7' high but you should be aware of setbacks in the front yards as well as corner lots. 
• No permit is needed in Kent County for a fence up to 7' unless* it is around a Pool or Daycare.
• Reference: "Kent County Levy Inspection & Enforcement" Fencing FAQ Kent County Gov

Sussex County

• Fences may reach a height of 7' on the back and sides lines. Unless on a corner lot.
• Maximum height in the front yard is 3.5' 
• Reference: "Sussex County Gov. Site" Sussex County Zoning Brochure

New Castle County 

• Legal height is 4'  
• All residential properties are permitted to have a fence but must be constructed of materials specifically for a fence.
• No fence shall exceed 6' in height unless for ballcourts.
• Reference: "New Castle County Gov. Site" FAQ All About Fences NCC

Be aware that neighborhoods with HOAs and/or being within city or town limits of Municipalities can be different as they tend to have their own set of regulations and setbacks. You should always reach out to them and look for any updates because requirements are subject to change.