21 Harbor Ave, Islip, NY 11751
Property image
Property image
OFF MARKET

21 Harbor Ave
Islip, NY 11751

  • 4 Beds
  • 2.5 Baths
  • 2,000 sqft

$921,700

Trulia Estimate
as of Aug 22, 2026
Est. Refi. Payment $6,166/mo*
Refinance Your Home

$921,700

Trulia Estimate
as of Aug 22, 2026
Est. Refi. Payment $6,166/mo*
Refinance Your Home
4 Beds
2.5 Baths
2,000 sqft

Home Value

Trulia Estimate
$922K
Since last month
Decreased$4K (-0.4%)
Since last year
Increased$53K (+6.1%)
Since last sale
Increased$373K (+67.9%)
Learn more about this home's value by checking out its Trulia Estimate, the value of nearby homes, and how much similar homes have sold for.

Trulia Estimate

The of this home's value increased by +114% in the last 10 years
MonthEstimated value
2026
August 2026$922K
July 2026$926K
June 2026$926K
May 2026$905K
April 2026$885K
March 2026$883K
February 2026$872K
January 2026$878K
2025
2024
2023
2022
2021
2020
2019
2018
2017
2016

Comparable sales

These are recently sold homes that have a similar location or other similar features to this home, like bedrooms, bathrooms, and square footage. Get a sense of the expected prices in the area by viewing these homes.
Address
Distance
Property Type
Sold Price
Sold Date
Bed
Bath
Sqft
136 Cedar Avenue, Islip, NY
0.14
Single-Family Home
$750,000
11/17/25
3
2.5
2,346
140 Ocean Avenue, Islip, NY
0.12
Single-Family Home
$835,000
01/27/26
4
2.5
2,676
2 Bay Place, Bay Shore, NY
0.27
Single-Family Home
$735,000
05/19/26
4
2
1,870
53 Church Avenue, Islip, NY
0.29
Single-Family Home
$698,000
10/01/25
4
2
1,937
77 Church Avenue, Islip, NY
0.26
Single-Family Home
$735,000
10/10/25
4
2.5
2,500
155 Smith Avenue, Islip, NY
0.30
Single-Family Home
$690,000
07/22/26
4
2
2,100
146 Smith Avenue, Islip, NY
0.27
Single-Family Home
$765,000
11/19/25
3
2.5
1,800
11 Doxsee Place, Islip, NY
0.06
Single-Family Home
$610,000
02/24/26
3
1
2,252
47 Smith Avenue, Islip, NY
0.35
Single-Family Home
$800,000
05/21/26
4
2
2,128
151 Church Avenue, Islip, NY
0.26
Single-Family Home
$950,000
07/13/26
4
2
2,450

Nearby home prices

Get a sense of expected prices in the area by checking the value of nearby homes.
Address
Distance
Price
Bed
Bath
Sqft
Status
1 Bayview Ave, Islip, NY 11751
0.06
$1,886,500
4
3.5
2,980
Off Market
11 Doxsee Place, Islip, NY 11751
0.06
$610,000
3
1
2,252
Recently Sold
29 Orowoc Drive, Islip, NY 11751
0.06
$584,200
2
1.5
1,354
Off Market
59 Harbor Avenue, Islip, NY 11751
0.10
$733,400
3
2
1,788
Off Market
50 Raymond Street, Islip, NY 11751
0.08
$988,300
7
3.5
2,372
Off Market
25 Bayview Avenue, Islip, NY 11751
0.12
$988,600
4
2.5
3,041
Off Market
52 Marvin Lane, Islip, NY 11751
0.13
$935,000
4
2.5
2,204
Recently Sold
0 Ocean Avenue, Islip, NY 11751
0.11
$1,165,200
5
5
-
Off Market
53 Raymond Street, Islip, NY 11751
0.13
$802,900
3
2
-
Off Market
140 Ocean Avenue, Islip, NY 11751
0.12
$835,000
4
2.5
2,676
Recently Sold
51 Marvin Lane, Islip, NY 11751
0.15
$914,700
5
2.5
2,517
Off Market
10 Maple Street, Islip, NY 11751
0.16
$1,397,500
5
3.5
3,308
Off Market

Local Information

  • Map ViewExplore the area around 21 Harbor Ave.
  • Schools2 Elementary Schools1 Middle School1 High School
  • Shop & Eat
-- mins to
Commute Destination

Home Highlights

Property Type
Single-Family Home
Year Built
1970
Living Area
2,000 sqft
Price/Sqft
$461
Parking
Garage

About this House

Beautifully Maintained 4 Bedroom 2.5 Bath Colonial Complete With Gleaming Wood Floors Thru-Out. Updated Kitchen, Den W/F.P., Full Basement, 2 Car Garage, Hot Tub On New Deck, Updated 200 Amp Electric On A Beautiful Block, 1 Block From The Water Located South Of Montauk In "Snug Harbor Area". Flood Zone: X
21 Harbor Ave, Islip, NY 11751 is a 4 bedroom, 3 bathroom, 2,000 sqft single-family home built in 1970. It last sold for $549,000 on Jul 27, 2018. It is currently off market. The Trulia Estimate is $921,700, with a rent estimate of $4,708/month.

Home Details for 21 Harbor Ave

Interior Features

Interior Details
BasementAtticTypes of Rooms: Dining Room, Family RoomCeiling Fan
Levels, Entrance, & Accessibility
Stories: 2Floors: Hardwood, Laminate
Appliances & Utilities
Cable ReadyDishwasherDryerRefrigeratorWasher
Fireplace & Spa
FireplaceHot Tub or Spa

Exterior Features

Exterior Home Features
Roof: AsphaltDeckExterior: Wood, BrickLawnSprinkler System
Parking & Garage
GarageParking Spaces: 2Parking: Garage Attached

Property Information

Year Built
Year Built: 1970
Property Type / Style
Property Type: Single Family HomeArchitecture: Colonial

Lot Information

Lot Area: 7405 sqft

Price and Tax history

DateEventPrice
Jul 27, 2018
Source: OneKey® MLS as distributed by MLS GRID #L3019196
Sold
$549,000
Apr 27, 2018
Source: Agent Provided
Pending
$549,000
Apr 4, 2018
Source: Agent Provided
Listed For Sale
$549,000

Market trends in Islip

Last updated July 2026
Buyer'sMarketSeller'sMarket
Avg. sale price
—
Sale-to-List Price
—
Price per sq ft
—
Available listings
36
6MoM

Around this home

What Locals Say about Islip

At least 118 Trulia users voted on each feature.

  • 90 % Say parking is easy

  • 90 % Say it's dog friendly

  • 88 % Say car is needed

  • 86 % Say there's holiday spirit

  • 85 % Say yards are well-kept

  • 75 % Say people would walk alone at night

  • 73 % Say kids play outside

  • 65 % Say neighbors are friendly

  • 64 % Say it's quiet

  • 63 % Say it's walkable to restaurants

  • 62 % Say streets are well-lit

  • 62 % Say they plan to stay for at least 5 years

  • 59 % Say there are sidewalks

  • 59 % Say it's walkable to grocery stores

  • 59 % Say there's wildlife

  • 49 % Say there are community events

Sourced by Trulia users. Learn more about our methodology.
  • Michellereid2323
    "Family-oriented neighborhood. Main Street is charming, walkable, and dotted with boutiques, cafes, and diners."
    0
    Flag
  • Matt Classie
    "Street fairs, events at Brookwood Hall during holidays. Theres lots to do in the town of Islip. Bats & Brews is a great event."
    0
    Flag
  • Yen160107
    "I have kids that play in the front yard and they step on the dog feces that they left behind. Also I have signs that say “kids at play” but they do not care"
    0
    Flag
  • Trulia User
    "The drive is horrible and the traffic which is 300 feet from your front door is deafening! A ten lane super hwy and that’s what you wake up to at 4:30 am every day ! Or you can take the train a mile away which you can also here every morning blasting it’s way to islip train station . "
    0
    Flag
  • Trulia User
    "Well celebrate almost all the events soccer games good school very friendly neighborhoods good shopping center "
    1
    Flag
  • Jamal G.
    "this neighborhood is a great place to live there are restaurants in the mall nearby good schools and they are also close"
    14
    Flag
  • Stephen B.
    "The taxes are very high here for the school. Bay Shore schools are just as good or better and the taxes are much lower. "
    9
    Flag
  • Michael .
    "Good! I work in the city and take the LIRR. The islip station has free parking and plenty of spaces."
    1
    Flag
  • Monmona
    "you need to have a car to commute around. around. if you live close enough to the Long Island Railroad, then you can walk to the station and take the train from there."
    1
    Flag
  • Fldsetter
    "I grew up here and actually bought my childhood home back after living in another part of the country . Beaches are close , most folks keep there homes well maintained . There are lot of children here and the schools are second to none . I wish the town would replace the roads here , and take better care of there pubic areas ! But let the young folks moving in fight that fight ! "
    1
    Flag
  • Djhafner132
    "5 min to train station.the neighbors are friendly.i am an avid fisherman and two fishing piers are less than a mile away.the streets are well treed and maintained "
    0
    Flag
  • Djhafner132
    "I lived here since 1973.The homes are well kept and neighbors are friendly.the town dock is an easy walk with great fishing the streets are well maintained.All in all a great place to live"
    0
    Flag
  • Djhafner132
    "Parades block parties great fishing close by.great south of montauk location.Great place to raise a family "
    0
    Flag
  • Ricktssf
    "I work locally, so I can walk to work. the train station to NYC is only 4 blocks away. easy commute on the train. "
    2
    Flag
  • G.Greco
    "I've made Islip my home since 1980. Yards are well kept, the streets are maintained, paved and cleaned regularly. The school district is good. It's a good place to live and raise a family. This area south of Montauk is very desirable"
    16
    Flag
  • Tannuramees
    "parades, fairs, shops close by, farmers market, good schools, nice neighborhood, school events, town events"
    1
    Flag
  • Catherine M.
    "I have lived here for 18 years and for the most part it’s a good area. I am not a huge fan of the school district but it’s not horrible either ."
    11
    Flag
  • Stefbartoli
    "Dog friendly neighborhood! People walk their dogs around regularly. Neighbors look out for each other’s pets as well. "
    1
    Flag
  • Tyase930
    "Quiet respectful neighbors. Walking distance to stores. Lots of new businesses and new development s."
    0
    Flag
  • Tony H.
    "I live in this neighborhood for 2 years so far people are very friendly, there's always parking, people walk their dogs at night and exercise regularly. It's pretty cool !!!"
    0
    Flag
  • Fldsetter
    "Crappy roads / rats / compact floresant lights instead of LED ( someone got paid off ) no trees left due to disease , and the town is not planting any ! Highway noise 10 lanes now on Sunrise HWY - RT27 . No plans for a sound wall ??? I guess we are lower class here in Islip . Airplane and helicopters all day and night fly over head ,, isn’t there a bay or ocean they can fly over then go straight up Lakeland Blvd to the airport ???? I will eave as soon as I find a house elsewhere and not in NY "
    0
    Flag
  • Ricktssf
    "I'm 17 years living in Islip. a little great Hamlet along the great South Bay. Town of Islip is much larger, but this is a Suburban area. "
    0
    Flag

LGBTQ Local Legal Protections

Frequently asked questions about 21 Harbor Ave

  • What is 21 Harbor Ave estimated to be worth?
    Trulia's estimated value for 21 Harbor Ave in Islip, NY is $921,700.
  • What is the price history for 21 Harbor Ave?
    21 Harbor Ave in Islip, NY last sold for $549,000 in July 2018.
  • Is Islip a buyer's or seller's market?
    Islip is currently a seller's market, based on recent for-sale activity.
  • What do residents say about Islip?
    Residents describe Islip, NY as easy to park in, dog-friendly, and well-kept. Most residents say you need a car. See recently sold homes in Islip, NY.
  • Does 21 Harbor Ave have laundry facilities?
    Yes, 21 Harbor Ave in Islip, NY has in-unit laundry.
  • How big is the lot at 21 Harbor Ave?
    The lot at 21 Harbor Ave in Islip, NY is about 0.18 acres (7,725 sq ft).

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