List of U.S. county secession proposals

Alabama

• Perdido County, Alabama would contain northern Baldwin County, divided by a straight line extending westward from the northwestern tip of Florida, and western Escambia County, west of Big Escambia Creek. The southwestern tip of Conecuh County, also west of Big Escambia Creek, may be included as well. The headwaters of the Perdido River rise near the center of this proposed county. The Perdido County seat would be Atmore. The county has been proposed by city of Atmore backers, who believe that their growing city of over 10,000 residents should be a county seat. Furthermore, county backers believe that Atmore belongs in the Mobile-Daphne-Fairhope metropolitan combined statistical area, which would become much more likely within its own exurban-leaning county. Brewton would remain the county seat of rural-leaning Escambia County. In addition to the incorporated city of Atmore, Perdido County would include the unincorporated communities of Blacksher, Canoe, Freemanville, Huxford, Nokomis, Perdido and Tensaw.

  Alaska

• Chugiak and Eagle River are communities along the Glenn Highway between Anchorage and the Matanuska-Susitna Valley. Originally farming and homesteading communities with a distinct identity, they became better known starting in the 1970s as bedroom communities of Anchorage, and are currently located within its city limits. In the wake of the incorporation of the Greater Anchorage Area Borough and subsequent efforts to merge the GAAB with Anchorage's city government, Chugiak and Eagle River residents began their own efforts to attempt to secede from the GAAB. The culmination of these efforts, the Chugiak-Eagle River Borough, incorporated on August 27, 1974, with an area of and an estimated population of 5,832, before the incorporation was invalidated by the Alaska Supreme Court on April 14, 1975. Five months later, the reconstituted GAAB and existing cities within its boundaries merged to form the Municipality of Anchorage. The population of Eagle River increased greatly during the 1980s and 1990s. This has led to renewed discussion during the 21st century on the part of Chugiak and Eagle River residents to secede from Anchorage.

  Arizona

• Russell Pearce, a state legislator, has proposed a bill which would ease county splits, as part of his effort to split off the East Valley portion of Maricopa County. Two such attempts were made: the first one in the early 1990s included the cities and towns of Mesa, Chandler, Gilbert, Queen Creek, Tempe, and Guadalupe, while a second attempt in the early 2000s included the same cities and towns except for Tempe and Guadalupe. County splitting rules were made more restrictive after the formation of La Paz County in 1983, which required a significant state investment to keep the county running as the result of its small tax base.
• There is an ongoing movement in Lake Havasu City to split from Mohave County.
• In the late 1930s, differences between mining and ranching interests in Cochise County spurred a proposal to split the county, with the new county's seat at Willcox, which the state Legislature ultimately rejected.
• Sierra Bonita County: proposed at the 13th Arizona Territorial Legislature in 1885, with Willcox proposed as the county seat. The proposal died by one vote.
• In the 1980s, a bill was passed in the state legislature to create an all Indian county out of the northern halves of Navajo and Apache Counties, and the northeastern half of Coconino County. Non-Indian communities in the southern region of these counties felt that the Navajo and Hopi Nations do not pay a fair share in local taxes. The bill was vetoed by then governor Bruce Babbitt, who placed a five-year moratorium on its consideration. Subsequent attempts to revive the bill failed and the issue has not resurfaced in recent years.
• Sitgreaves County, to be formed from the southern portions of Navajo and Apache Counties.
• Butte County: In 1897, James C. Goodwin, with the support of Charles T. Hayden and others, introduced a bill at the Territorial Legislature to split Maricopa County into two, with Tempe being the county seat. There have also been proposals, introduced in 1900 and 1913, to divide Maricopa County, with Mesa as the new county's seat.
• Mogollon County, Hohokam County, and O'odham County, to be formed from parts of Maricopa County. Proposals were introduced in 2023 by Republicans Alexander Kolodin and Jake Hoffman. Proposals to split Maricopa County had previously existed, but gained more support and attention following the 2020 presidential election.

  Arkansas

• Red River County, to be formed in 1871 from Lafayette County.

  California

• In Northern California, four proposed county plans failed in the 1990s: Redwood County, Tahoe County, Central Valley County, and Sequoia County.
• In Southern California, there are 6 proposed counties across the Los Angeles Metropolitan Area, within Los Angeles County and Orange County.
• Prior to the formation of Orange County, residents of Anaheim in 1870 pushed a bill in the state assembly for the creation of an Anaheim County. The proposal had the support of San Francisco.
• An attempt in the late 19th century to create San Antonio County in present-day Los Angeles and San Bernardino counties.
• In 1974, a referendum was held in El Dorado County for the secession of South Lake Tahoe County around the South Lake Tahoe. The referendum failed 46–54. Consequent proposals for a Tahoe County or High Sierra County in El Dorado, Placer County, Nevada County, and Sierra County have occasionally resurfaced when issues in the Central Valley basin conflict with issues in the more mountainous Lake Tahoe region.
• Mission County, to be formed from the northern portion of Santa Barbara County. A formal proposal was resoundingly rejected by voters in 2006. An earlier attempt in 1978 would have produced Los Padres County.
• In 1988, there was a serious effort, including a vote on the subject, to divide San Bernardino County into its urban southwestern corner, which would have retained the name, and a new Mojave County to comprise the vast, sparsely populated northern and eastern portions.
• High Desert County, to be formed largely from northern Los Angeles County as well as portions of San Bernardino County and Kern County. Proposed by late state senator Pete Knight in 2002.
• In the late 1980s, some residents of the Coachella Valley of Riverside County failed to create a new county: Cahuilla County.
• A writer to the Los Angeles Times in 1997 indicated a sentiment from south Orange County residents that they would seek to secede from the county if it insisted on building a new airport on the former site of Marine Corps Air Station El Toro. The airport plan was eventually discarded in favor of the Orange County Great Park plan.
• In 2002, residents of the city of Corona proposed Corona County to include the western edge of Riverside County.
• In 2014, residents of rural East County San Diego proposed to secede from San Diego County, with the proposed name of Chaparral County.

  Colorado

• Platte County, authorized to be formed from Weld County in 1872 but never organized and then repealed in 1874.

  Delaware

• After 2000, a fourth Appoquinimink County was proposed to be carved out of New Castle County. The effort intended to end the zoning restrictions of the Unified Development Code on the undeveloped farmland. The proposed boundaries extended beyond the Appoquinimink Hundred to include all land south of the C&D Canal, with Middletown as the proposed seat.

  Florida

• Two attempts to form a separate county combining parts of Levy and Marion Counties took place. The first one was Bloxham County, and the second was Call County.
• Three attempts to form a separate county combining parts of Dade and Monroe Counties took place in 1915, 1925 and 1949; the county was to be known as Redland County and Homestead was selected as its county seat.
• In 1930, an attempt to form a county out of Palm Beach County between the Palm Beach and Hillsboro Canals was proposed with Lake Worth as its county seat. The county was never named.
• In 1947, Miami Beach attempted to form a separate city-county from parts of Dade County, with Bal Harbour, Surfside, Bay Harbor Islands, and Indian Creek also being invited to join this new entity.
• In 1960, Miami Beach and other municipalities along the Atlantic coast, unhappy with the government structure introduced by the 1957 adoption of a charter in Dade County, unsuccessfully sought to break away as a separate county.
• In 1999, a bill was introduced in the Florida Legislature that would have allowed the City of Hialeah to vote on seceding from Miami-Dade County to form a new county.
• In the early-1990s, members of the coastal communities of Duval County that rejected consolidation with Jacksonville planned to form Ocean County.
• An attempt was made in 1935 to split off the western half of Palm Beach County lying west of Twentymile Bend into a new county, due to residents of Pahokee being dissatisfied with the poor roads and distance to Palm Beach County's seat, West Palm Beach; the county's name and its seat were never chosen.
• In 1977, the Boca Raton City Council proposed the secession of Southern Palm Beach County into a new county, due to how large, inefficient, and negligent they felt the county was at the time; the county's name and its seat were never chosen.
• Due to major differences between the south end of the county and the north end, some individuals have suggested that the south end of Santa Rosa County should break off as its own. However, while this has been suggested by some, no major or organized effort has been made to enact such actions. Names like Fairpoint County and Reagan County have been proposed, but no name has been really pushed as part of these suggestions.
• The City of Ocoee made an attempt in April 1980 to secede from Orange County due to local disdain for the county's behavior towards the city.
• The residents of Hastings tried seceding to form Hastings County, which was to be carven from Putnam and Saint John's Counties, in 1917 and 1922.
• In 1887, a bill was introduced in the Florida Legislature that would have created a Perry County from Alachua, Bradford, Clay and Putnam Counties; a second attempt to create a county from this same area - named Santa Fe County - was later proposed in 1913.
• An attempt was brought forward in 1983 to split the northern half of Lee County lying north of the Caloosahatchee River into a new county called Calusa County, with Cape Coral selected as the county seat.
• In 2021, a movement attempted to create Springs County from the communities of Newberry, High Springs, Alachua, Archer, LaCrosse, and parts of Gainesville from Alachua County.