Nottinghamshire will open their County Championship title defence at Somerset in early April to kick off the first of three blocks of fixtures announced by the ECB on Thursday.
Leicestershire and Glamorgan, both back in Division One for the first time in more than two decades, host Sussex and Yorkshire respectively in the opening round from April 3.
Nottinghamshire won their first Championship trophy for 15 years and seventh overall last season when their South African wicketkeeper, Kyle Verreynne, hit a six to secure a batting bonus point and top spot in Division One on the penultimate day of the 2025 season.
The 2026 Rothesay County Championship will be played in three blocks of matches - with each side playing a total of 14 times after counties rejected a proposal earlier this year to cut the number of first-class games to 13.
Each county will play six matches during the first seven-week block, with all matches during that period starting on a Friday. A mid-summer block will be staged in June with each county playing twice while a third block of matches begins on August 20 with each team playing six matches. The final round begins on September 24.
Lancashire, winners of the Metro Bank One-Day Cup Women's Competition and the Vitality T20 Women's County Cup, will begin their 50-over title defence away to Durham on April 11 ahead of a historic first professional Roses clash with Yorkshire at Emirates Old Trafford on April 25.
Yorkshire, the 2025 Metro Bank One-Day Cup Women's League 2 champions, begin life as a Tier 1 side away to Somerset after their elevation to the top flight was brought forward by one year following a restructure of the women's domestic competition ahead of last season.
Men's One-Day Cup champions Worcestershire Rapids will begin their 2026 campaign at home to Derbyshire Falcons on July 24, with groups randomly drawn and each county playing once against every team in their group.
Gloucestershire, Kent Spitfires, Lancashire, Leicestershire Foxes, Northamptonshire Steelbacks, Notts Outlaws, Somerset, Surrey and Warwickshire make up Group A while Group B comprises Derbyshire Falcons, Durham, Essex, Glamorgan, Hampshire, Middlesex, Sussex Sharks, Worcestershire Rapids and Yorkshire.
The One-Day Cup Women's final will be played at the Utilita Bowl in Southampton on Saturday, September 19 followed by both the men's final at Trent Bridge and the Women's League 2 Final at Seat Unique Stadium in Bristol the following day.
The second season of the Vitality T20 Women's County Cup will involve 37 counties vying for a place on finals day at Emirates Old Trafford on August 29, including inaugural champions Lancashire Thunder.
The opening round, from April 26, features 28 counties before the nine Tier 1 counties - Durham, Essex, Hampshire, Lancashire Thunder, Somerset, Surrey, The Blaze, Warwickshire and Yorkshire - enter the competition in Round 3 from June 21.
Two all-Tier 1 ties have been confirmed for Round 3 with The Blaze at home to Durham and Yorkshire hosting Somerset.