The Honda Z-Series refers to the lineage of mini bikes manufactured by Honda Motorcycles. They are some of the most popular mini bikes of all time. Though their official model designations are typically Z50A, Z50J, Z50M, Z50R and ZB50, they are more commonly referred to as the "Monkey" or "Gorilla" because of the way people are said to look when riding one of such bikes.

Most Z-series bikes are small, light, collapsable motorcycles made for convenience and ease of transportation. Their outstanding feature is a 50cm3 4-stroke-engine with an over head camshaft. Some have a centrifugal clutch and three gear manual transmission, while others have a semi-automatic easy-shift transmission for learners.

The first original model of the Honda Z-series was originally produced as a children's ride at a Japanese amusement park, but was eventually refined and put into mass production, hitting the European market in 1967. Since then Honda has produced a wide variety of Honda Z-series mini bikes, but are currently no longer manufacturing new ones as part of their standard motorcycle line-up. Today, replica versions of this bike are being manufactured under the Jincheng Motors China name.

Original Honda Z-Series bikes are becoming increasingly rare, and are typically used as restoration projects by Honda Mini Trail enthusiasts in attempt to preserve their historic value.

Facts about history
1967 March start of sales (Z50M)
1969 July next release (Z50A)
1970 April (Z50Z)
1974 February (Z50J)
1978 August (Z50J-1) and start of sales for the Gorilla
1979 Monkey Limited (Z50J-1)
1981 March Black Monkey (Z50J-1) and Black Gorilla (Z50J-III)
1984 October Gold Monkey
1984 April next Gorilla release (Z50J-III)
1985 May next Monkey release (Z50J-1)
1987 March Monkey R
1988 Gorilla White (Z50J-III)
1988 Monkey RT
1990 January Monkey Special
1990 Stop of sales for the Gorilla
1991 February Monkey Baja (Z50J-1)
1992 Monkey (Z50R)
1996 Monkey Limited (Z50J-1)
1997 February Monkey Special
1998 February restart of sales for the Gorilla
2001 Stop of sales for the Monkey Baja