The man and woman have been released on bail while forensic tests are carried out on the suspected class B drugs.
As reported previously, the prison is one of 10 chosen by the Government to take part in a £10m pilot project to tackle drugs and violence inside jails.
A Leeds West Policing Team spokesman said: “A male and female were arrested on Saturday trying to take controlled drugs into HMP Leeds in order to pass the drugs to an inmate. A quantity of class B drugs were seized. The male and female have been bailed for forensic tests to be made on the drugs.
“At HMP Leeds, daily random searches are made of visitors and drugs dogs are also used. If any indications are given by the drugs dog, that person will be fully searched.”
Over the same period, 31 percent of the mandatory drug tests conducted in HMP Leeds returned a positive result, figures from the Ministry of Justice show.
The situation at HMP Leeds reflects the national picture, with 20 per cent of all drug tests carried out in prisons in England and Wales during the same period being positive.