Date
Details
Price
Change
Source
9/23/2026
Listed
$1,400,000
—
MLS
Disclaimer: Historical sales information is derived from public records provided by the county offices. Information is not guaranteed and should be independently verified.
This is a carousel with tiles that activate property listing cards. Use the previous and next buttons to navigate.
1/24
$1,400,000
This is a carousel with tiles that activate property listing cards. Use the previous and next buttons to navigate.
1/24
Property Description
644 William Street The property being sold is 644 William Street. The current property record/card reflects both 644 and 646 William Street, although the property being conveyed is 644 William Street. The structure at 644 William Street is a two-and-a-half-story home currently configured as a duplex and is in need of renovation. The first floor consists of two bedrooms and two bathrooms. The second floor contains two bedrooms and one bathroom. A stairwell provides access to the third floor, which is currently unfinished and is not completed or configured as living space. In its current condition, the property contains four bedrooms and three bathrooms of finished living area, with additional unfinished space on the third floor. The property is currently being used/configured as a duplex and will require renovation.
Full Property Details
Full Property Details for 646 William St
General
- Price: $1,400,000
- Taxes: $13,849 (2025)
- Status: Active
- Type: Duplex
- Source: 927
- MLS ID: 621406
- Updated: 9/25/2026
- Added to Site: 13 day(s) ago
Interior
- Flooring: Combo
Rooms
Bathrooms
- Total Bathrooms: 2
- Full Bathrooms: 2
Bedrooms
- Total Bedrooms: 3
Additional Information
- Security/Safety: No Security
Exterior
- Deck/Patio: Open Porch/Balcony
- Porch/Patio/Deck: Open Porch/Balcony
Parking
- Parking Features: Off Street
Location
- Area: 02 - Key West
- County: Monroe
- Subdivision: Old Town - Unlisted (1.0)
Community
- Assoc. Fees Include: None
- Pets Allowed: Yes
Heating & Cooling
- Air Conditioning: Yes
- Cooling Type: Wall/Window Unit(s)
- Heating Type: Hot Water
Structural Information
- Architectural Style: Above Flood, Conch
- Construction Status: Fixer
- Construction: Frame
- Roof: Metal
- Windows/Doors: Wood Windows, Shutters
- Square Feet: 1,780
- Sq. Ft. Source: Property Data Card
- Year Built: 1928
- Property Condition: Fixer
Lot Features
- Property View: No Waterview
- Lot Size (Acres): 0.09
- Lot Size (Sq. Ft.): 4,116
- Lot Dimensions: 65 x 78
- Zoning: HHDR - Historic High Density Residential
Water Features
- Water View: Yes
Financial Considerations
- Tax Amount: $13,849.76
- Tax Year: 2025
- Terms: Cash, Conventional
Disclosures and Reports
- Legal Description: Kw Pt Of Tr 5 C3-569
- APN: 18810000000
Listed by Coldwell Banker Schmitt Real Estate Co. (KW), Louis M Paez (305) 395-1081
We Value Your Privacy
We Value Your Privacy
We Value Your Privacy
Listing agent
— 646 William St —
Louis M Paez
Coldwell Banker Schmitt Real Estate Co. (KW)
NMLS#: 1598647Get Pre-Approved Today
Schools
Schools serving 646 William St
School District:Monroe County School District, Middle Torch Key, FL
| Name | Grades | Distance |
|---|---|---|
Horace O'bryant School 1105 Leon Street, Key West, FL 33040 | 6-8 | 0.7 mi |
Key West High School 2100 Flagler Avenue, Key West, FL 33040 | 9-12 | 1.3 mi |
Disclaimer:
School attendance boundaries provided by ATTOM Data Solutions and are for reference only. Contact the school directly to verify enrollment eligibility.
Price & Sales History for 646 William St
Tax History
Tax History for 646 William St
Year
Property Taxes
Change
Tax Assessment
Change
2025
$13,850
9%
$1,567,206
2%
2024
$12,760
4%
$1,533,811
—
2023
$12,267
28%
$1,530,403
70%
2021
$9,614
-9%
$902,442
-24%
2022
$10,540
10%
$1,181,793
38%
2021
$9,614
5%
$855,275
1%
2019
$9,141
—
$847,153
9%
2018
$9,109
3%
$779,811
-15%
2017
$8,829
7%
$912,984
24%
2016
$8,215
3%
$737,413
26%
2015
$7,973
9%
$585,884
10%
2014
$7,317
5%
$532,622
10%
2013
$6,983
—
$484,202
—
Disclaimer: Historical tax information is derived from public records provided by the county offices. Information is not guaranteed and should be independently verified.
Estimate the Cost
Estimate the Cost for 646 William St
This is a carousel with tiles that activate property listing cards. Use the previous and next buttons to navigate.
This is a carousel with tiles that activate property listing cards. Use the previous and next buttons to navigate.
- Single Family
- Active
- Updated 5 days ago
- 3Beds
- 3Total Baths
- 1,589Sq. Ft.
- Single Family
- Active
- Updated 2 days ago
- 2Beds
- 1Total Bath
- 975Sq. Ft.
This is a carousel with tiles that activate property listing cards. Use the previous and next buttons to navigate.
- Mobile Home
- Active
- Updated 6 days ago
- 3Beds
- 3Total Baths
- 1,222Sq. Ft.
- Mobile Home
- Active
- Updated 4 days ago
- 1Bed
- 1Total Bath
- 408Sq. Ft.
- Lots/Land
- Active
- Updated 1 day ago
- 0.14Acres
Listed by Keller Williams Island Life Real Estate
This is a carousel with tiles that activate property listing cards. Use the previous and next buttons to navigate.
646 William Street, Key West, FL 33040 (MLS# 621406) is a Duplex property with 3 bedrooms and 2 full bathrooms. 646 William Street is currently listed for $1,400,000 and was received on September 23, 2026. Want to learn more about 646 William Street? Do you have questions about finding other Duplex real estate for sale in Key West? You can browse all Key West real estate or contact a Coldwell Banker agent to request more information.