Key Colony Beach is a small, incorporated municipality in Monroe County, Florida, located in the middle of the Florida Keys. It sits on Shelter Key (and a small portion of Fat Deer Key), connected to Marathon via the Sadowski Causeway. The city was originally a low-lying 97-acre island that was expanded and raised to 6 feet above sea level through dredging by developer Phil Sadowski in the early 1950s. It was officially incorporated on September 24, 1957, after residents voted to remain independent rather than join Marathon.
Demographics and Geography:
Population: Approximately 790–921 year-round residents (2020–2025 estimates), swelling to 2,500–4,000 during the winter tourist season.
Area: The city covers 0.65 square miles, with 32% being water.
Income: High median household income, estimated around $126,525 (2025), with a median home value near $1,077,273.
Climate: Features a tropical savanna climate (Köppen Aw), unique among the 48 contiguous states.
Notable Features and History:
Hurricane Donna (1960): Devastated the city, but its incorporated status allowed it to secure direct federal grants for rebuilding, fostering strong community resilience.
Nicknames: Often called the “Gem of the Florida Keys” due to its walkable layout and relaxed island lifestyle.
Recreation: Offers direct access to the Gulf of Mexico and Atlantic Ocean, with facilities including a par-3 golf course, tennis/pickleball courts, and numerous parks like Sunset Park.
Incidents: Sunset Park is known as the site where a woman was fatally struck by a spotted eagle ray in 2008, highlighting the area's proximity to marine wildlife.
Key Buildings: Notable landmarks include the Key Colony Beach Motel, Key Colony Beach Club, and the municipal buildings on West Ocean Drive.
According to Redfin, the median sale price reached $1.1 million last month, representing a significant 46.3% increase year-over-year, with the median price per square foot at $763 (up 26.5% since last year). However, Zillow reports a different picture, with the average home value at $879,207, indicating a 6.3% decline over the past year.
The broader Florida luxury market has been performing strongly in 2026, with statewide sales in the $3-5 million range surging nearly 69%, while the $1.5-2 million category rose 61% compared to early 2025. Single-family homes priced between $5-10 million jumped more than 31% during the same period. This luxury segment growth contrasts with the overall Florida housing market, which has been stabilizing with the statewide median sale price for single-family homes at approximately $420,000 as of April 2026 (up just 1.8% year-over-year).
Florida's luxury market continues its upward trajectory, driven by robust demand and constrained inventory at the highest tiers, which fuels competitive bidding for exceptional properties. This trend is particularly evident in South Florida, where the luxury tier median reached $4,957,799 in April 2026, up 12.8% year-over year, even as the broad Miami-Dade median sale price decreased slightly to $573,398.
