diff --git a/r/R/dataset.R b/r/R/dataset.R
index 90e6516927e5d..2400d0839351b 100644
--- a/r/R/dataset.R
+++ b/r/R/dataset.R
@@ -112,7 +112,8 @@
 #' * "csv"/"text", aliases for the same thing (because comma is the default
 #'   delimiter for text files
 #' * "tsv", equivalent to passing `format = "text", delimiter = "\t"`
-#'
+#' * "json", for JSON format datasets Note: only newline-delimited JSON (aka ND-JSON) datasets
+#'   are currently supported
 #' Default is "parquet", unless a `delimiter` is also specified, in which case
 #' it is assumed to be "text".
 #' @param ... additional arguments passed to `dataset_factory()` when `sources`
diff --git a/r/man/open_dataset.Rd b/r/man/open_dataset.Rd
index 94b537a1d38c6..7c3d32289f73e 100644
--- a/r/man/open_dataset.Rd
+++ b/r/man/open_dataset.Rd
@@ -74,10 +74,11 @@ only version 2 files are supported
 \item "csv"/"text", aliases for the same thing (because comma is the default
 delimiter for text files
 \item "tsv", equivalent to passing \verb{format = "text", delimiter = "\\t"}
-}
-
+\item "json", for JSON format datasets Note: only newline-delimited JSON (aka ND-JSON) datasets
+are currently supported
 Default is "parquet", unless a \code{delimiter} is also specified, in which case
-it is assumed to be "text".}
+it is assumed to be "text".
+}}
 
 \item{factory_options}{list of optional FileSystemFactoryOptions:
 \itemize{