Yamaha Y125Z or better known as Yamaha Z (in Europe, Thailand and Vietnam) is a 125 cc two-stroke moped or underbone motorcycle produced by Yamaha. Debuted in 1998 as a successor of Yamaha Y110SS, the Y125Z was the first two-stroke underbone motorcycle with an YEIS catalytic converter.^{[citation needed]} Beside being sold in most Southeast Asian countries especially in Malaysia and Singapore, it was also sold in Greece. The production of the Y125Z ended in 2017 after being sold for more than two decades.^[3]

The Yamaha Y125Z is widely used in motorcycle racing tournaments held in Malaysia or Asean level. In Malaysia, the Y125Z is formerly used in the Expert category of Malaysian Cub Prix tournament series.^{[citation needed]}