Cock Beck is a stream in the outlying areas of East Leeds, West Yorkshire, England, which runs from its source due to a runoff north-west of Whinmoor, skirting east of Swarcliffe and Manston (where a public house has been named 'The Cock Beck'), past Pendas Fields, Scholes, Barwick-in-Elmet, Aberford, Towton, Stutton, and Tadcaster, where it flows into the River Wharfe.

It is a tributary of the River Wharfe, formerly known as the River Cock or Cock River, having a much larger flow than today. The name 'cock' may refer to a mature salmon, as it was a spawning ground for salmon and trout. Industrial pollution reduced the fish stock, but it has been recovering in the 21st century, aided by work from the Environment Agency. In places the beck was relatively narrow, but too deep to cross unaided; a feature which can still be seen today at many points.