The 2008–09 RBS Twenty-20 Cup was the fourth season of the RBS Twenty-20 Cup in Pakistan, sponsored by Royal Bank of Scotland.

The Sialkot Stallions won their third overall and consecutive title by defeating the Karachi Dolphins in the final.

As the winners, the Stallions qualified for the 2008 Champions League Twenty20, which was later cancelled.

[2] The position of the teams in the points table is determined by: The prize money was increased from the previous edition.

[3] The top team from each group qualify for the semi-finals.