Triple Nine (Chinese: 九九九行动) is an English language television police procedural telecast on what was then the Television Corporation of Singapore's Channel 5 (today's MediaCorp TV Channel 5) from 1995 to 1999. As the station's earliest attempt in an action-based drama series, the series revolved around the lives of a group of police officers, namely Inspector Mike Chin (James Lye), Inspector Elaine Tay (Wong Li Lin), and Sergeant Alan Leong (Lim Yu Beng) from the Special Investigation Section of the CID.
The cast changed in subsequent seasons, notably with the inclusion of Inspector Sean Han (Robin Leong), Inspector Herbert de Souza (Mark Richmond), and Sergeant Yeo Lay Kim (Chong Chia Suan) from the third season, and Sergeant Sarah Chan (Annabelle Francis) from the 4th season. Season 2 was written by Amos Kwok.
Season 3 was originally aired from 21 July 1998.