CSA 4-Day Series Division 1 (Saudi Arabia) 2025/26

The CSA 4-Day Series serves as the premier first-class cricket competition in South Africa. Organized by Cricket South Africa (CSA), it stands as the top tier of the country's domestic cricket pyramid. The tournament carries a heritage that reaches back to the historic Currie Cup, which was first contested in the 1889–90 season. That original trophy was donated by Sir Donald Currie, founder of the Castle Shipping Line, following the 1889 English cricket tour of South Africa. The inaugural match was played between Transvaal and Kimberley.

Following structural reforms in 2004, the competition transitioned to a franchise-based system, undergoing several name changes including the Sunfoil Series. In 2021, CSA reverted to a provincial structure, renaming the tournament the CSA 4-Day Series to reflect the four-day duration of the matches. The current Division One features six teams: Boland, Dolphins, KwaZulu-Natal Inland, Lions, North West, and Titans. The season follows a round-robin league stage, culminating in a final between the top two teams in the points table. Points are awarded for wins and draws, with additional bonus points for batting and bowling performances.

Promotion and relegation between Division One and Division Two are determined by an aggregate points system across all three CSA domestic formats. For the 2025–26 season, KwaZulu-Natal Inland and Northern Cape were promoted from Division Two, replacing Warriors and North West Dragons. Historically, the Lions franchise is the most successful team in the provincial era, winning 25 titles outright and sharing four between 1889 and 2005. In the 2024–25 season, the Lions and Titans drew the final, resulting in a shared title. The Lions were the champions in 2022–23, and the Titans in 2023–24. This competition is distinct from the CSA One-Day Cup and the CSA T20 Challenge, representing the traditional red-ball format of the sport.