RJDemetra is a R interface to JDemetra+, the seasonal adjustment software officially recommended by Eurostat and the European Central Bank (ECB) to the members of the European Statistical System (ESS) and the European System of Central Banks (ESCB). JDemetra+ is a developed by the National Bank of Belgium (NBB) in cooperation with the Deutsche Bundesbank with the support of Eurostat, in accordance with the ESS Guidelines on Seasonal Adjustment. It implements the two leading seasonal adjustment methods TRAMO/SEATS+ and X-12ARIMA/X-13ARIMA-SEATS. RJDemetra is a R package that offers full access to all JDemetra+ options and outputs. It also offers many possibilities to the users to implement new tools for the production of seasonally adjusted series thanks to all the libraries already available in R.