[23] Sea Isle City is located on Ludlam Island, which also contains the Strathmere section of Upper Township.

Sea Isle City was originally incorporated as a borough on May 22, 1882, from portions of Dennis Township, based on the results of a referendum held six days earlier.

[26] Sea Isle City was founded in 1882 by Charles K. Landis, who was also the founder of Vineland, New Jersey.

A non-profit group, The Friends of the Ludlam Beach Lighthouse, was unsuccessful in its efforts to raise enough money to save the building from demolition by moving it to a new location and restoring it.

It was struck by a Silkworm missile off Kuwait on October 16, 1987, wounding 18 crew members and seriously damaging the ship.

[28] There have been many hurricanes and huge storms that have hit the small island of Sea Isle City, New Jersey.

The storms of the 1890s, 1920s, and the 1944 Great Atlantic Hurricane have been some of the worst natural disasters to hit the coast of New Jersey.

Many people evacuated in time to save their lives, but came back to find their homes and assets destroyed.

[29] About a week later when the storm had subsided, Sea Isle City citizens moved back into their homes and began the needed revisions.

As a result of the storm, a "dune line" was formed, and this caused beachfront businesses and homes to move back from the shoreline an average of one block.

In 2002, the printed message on its signature water tower was changed from "Welcome to Sea Isle City" to "Smile!

[30] The city hosts a Polar bear plunge every February, holding the 25th annual event in 2019, featuring many participants dressed in costume.

Funland was permanently removed, however, following the 2013 summer season for financial reasons in part due to losses from Hurricane Sandy.

[32] In 2011, Sea Isle City began a $14 million makeover to create a public corridor from the bay to the ocean.

Plans included a new boathouse on the marina, installing a new playground and basketball courts on JFK Boulevard and erecting a pavilion and band shell at Excursion Park on the city's Promenade overlooking the Atlantic Ocean.

The mayor and council members serve four-year terms of office and are chosen at-large on a non-partisan basis as part of the May municipal elections.

[52][53] As of July 2023[update], the Mayor of Sea Isle City is Leonard C. Desiderio, whose term of office ends on June 30, 2023.

[60][61][62] For the 119th United States Congress, New Jersey's 2nd congressional district is represented by Jeff Van Drew (R, Dennis Township).

[64] For the 2024-2025 session, the 1st legislative district of the New Jersey Legislature is represented in the State Senate by Mike Testa (R, Vineland) and in the General Assembly by Antwan McClellan (R, Ocean City) and Erik K. Simonsen (R, Lower Township).

[65] Cape May County is governed by a five-person Board of County Commissioners whose members are elected at-large on a partisan basis to three-year terms of office on a staggered basis, with either one or two seats coming up for election each year; At an annual reorganization held each January, the commissioners select one member to serve as director and another to serve as vice-director.

[66] As of 2025[update], Cape May County's Commissioners are Director Leonard C. Desiderio (R, Sea Isle City, 2027),[67] Robert Barr (R, Ocean City; 2025),[68] Will Morey (R, Wildwood Crest; 2026),[69] Melanie Collette (R. Middle Township; 2026),[70] and Vice-Director Andrew Bulakowski (R, Lower Township; 2025).

[83] In the 2004 presidential election, Republican George W. Bush received 61.7% of the vote (1,041 ballots cast), outpolling Democrat John Kerry, who received 37.0% (625 votes), with 1,687 ballots cast among the city's 2,177 registered voters, for a turnout percentage of 77.5.

Sea Isle City had been spending as much as $35,000 per student and hoped to see savings through the merger, even after adding in transportation costs.

[96] In March 2023, the Sea Isle City Public School was demolished to clear ground for a planned $20 million community center due to be completed in 2025.

There are numerous signs in the city to watch for turtle crossings in order to prevent further endangerment of the species.

[118][119] However, due to weight restrictions on the Townsend Inlet Bridge, New Jersey Transit 315/319 bus service only stops on Central Avenue and JFK Boulevard.

[124] The West Jersey and Seashore Railroad tracks branched from the Cape May Line at Sea Isle Junction, and entered the city at 41st Street, from where it continued south to Stone Harbor.

[125] The train was in use from the early 1900s until the mid-1930s after the merger of the two railroads when the tracks were removed and the streets were paved due to increased use of cars.

The plant hardiness zone at Sea Isle City Beach is 7b with an average annual extreme minimum air temperature of 5.5 °F (−14.7 °C).