50 series

50 series may refer to:

Electronics

 * HP 49/50 series, a type of graphing calculator made by Hewlett-Packard

Trains

 * 1–50 series (CTA), a retired subway car type for the Chicago Transit Authority
 * EMD SD50, also known as "50 series", a North American diesel locomotive type made by Electro-Motive Diesel
 * Kyoto Municipal Subway 50 series operating for the Kyoto Municipal Subway

Trucks

 * Dodge 50 Series, a box truck model operating in Europe