In the elections to the Florida State Senate that were held on November 6, 2018, 20 of the 40 seats were contested in regular elections and two seats in special elections. The winners of the 20 regular elections would serve four-year terms from November 6, 2018, to November 6, 2022, and the winners of the two special elections would serve two-year terms from November 6, 2018, to November 6, 2020.
There were no Democrats term-limited from their seats.
Seats where the margin of victory was under 10%:
District 2 consists of Bay, Holmes, Jackson, Walton, and Washington counties, and part of Okaloosa County. Incumbent George Gainer was re-elected by a margin of 51 percent.
Incumbent George Gainer won the primary unopposed.
Attorney Gigi Gibson won the primary unopposed.
MCI Maps gave the second district a rating of "Safe GOP".
District 4 consists of Nassau County and part of Duval County counties. Incumbent Aaron Bean was re-elected by a margin of 29 percent.
Incumbent Republican Aaron Bean defeated challenger Carlos E. Slay in the Republican primary by a margin of 75 percent.
District 6 consists of part of Duval County. Incumbent Audrey Gibson was re-elected unopposed.
District 8 consists of Alachua and Putnam counties, and part of Marion County. Incumbent Keith Perry was re-elected by a margin of one percent.
District 10 consists of Citrus and Hernando counties, and part of Pasco County. Incumbent Wilton Simpson was re-elected by a margin of 30 percent.
District 12 consists of Sumter County, and parts of Lake, and Marion counties. Incumbent Dennis Baxley was re-elected by a margin of 31 percent.
District 14 consists of parts of Brevard and Volusia counties. Incumbent state senator Dorothy Hukill, Republican, died on October 2018 from cervical cancer. As her name was already printed on ballots, votes cast for her were counted for Tom A. Wright, the Republican nominee, who won the election by a margin of 13 percent.
District 16 consists of parts of Pasco and Pinellas counties.
District 18 consists of part of Hillsborough County.
District 20 consists of parts of Hillsborough, Pasco, and Polk counties.
District 22 consists of parts of Lake and Polk counties.
District 23 consists of Sarasota County and part of Charlotte County. An election for this district was not scheduled to occur until the 2020 general elections, but a special election was scheduled concurrent with the 2018 general elections due to a vacancy that occurred as a result of the resignation of then-state senator Greg Steube to run for the United States House of Representatives.
District 24 consists of part of Pinellas County.
District 25 consists of Martin and St. Lucie counties, and part of Palm Beach County. An election for this district was not scheduled to occur until the 2020 general elections, but a special election was scheduled concurrent with the 2018 general elections due to a vacancy that occurred as a result of the resignation of former Senate President Joe Negron.
District 26 consists of DeSoto, Glades, Hardee, Highlands, and Okeechobee counties, and parts of Charlotte, Lee, and Polk counties.
District 28 consists of Collier and Hendry counties, and part of Lee County.
District 30 consists of part of Palm Beach County.
District 32 consists of part of Broward County. Incumbent Lauren Book was elected unposed both in the primary and general election.
District 34 consists of part of Broward County.
District 36 consists of part of Miami-Dade County.
District 38 consists of part of Miami-Dade County. Democrat Jason Pizzo beat incumbent Daphne Campbell in the Democratic primary, 54%-46%. The general election was cancelled, meaning Pizzo was the victor of the race.
District 40 consists of part of Miami-Dade County.