diff --git a/NEWS.md b/NEWS.md
index 3ac733842e..dc43b0f7e0 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,5 +1,10 @@
 # ggplot2 (development version)
 
+* You can now omit either `xend` or `yend` from `geom_segment()` as only one
+  of these is now required. If one is missing, it will be filled from the `x`
+  and `y` aesthetics respectively. This makes drawing horizontal or vertical
+  segments a little bit more convenient (@teunbrand, #5140).
+  
 * New `plot.tag.location` in `theme()` can control placement of the plot tag
   in the `"margin"`, `"plot"` or the new `"panel"` option (#4297).
 
diff --git a/R/geom-segment.R b/R/geom-segment.R
index a80bf84fa5..611ba85e2c 100644
--- a/R/geom-segment.R
+++ b/R/geom-segment.R
@@ -102,11 +102,13 @@ geom_segment <- function(mapping = NULL, data = NULL,
 #' @usage NULL
 #' @export
 GeomSegment <- ggproto("GeomSegment", Geom,
-  required_aes = c("x", "y", "xend", "yend"),
+  required_aes = c("x", "y", "xend|yend"),
   non_missing_aes = c("linetype", "linewidth", "shape"),
   default_aes = aes(colour = "black", linewidth = 0.5, linetype = 1, alpha = NA),
   draw_panel = function(self, data, panel_params, coord, arrow = NULL, arrow.fill = NULL,
                         lineend = "butt", linejoin = "round", na.rm = FALSE) {
+    data$xend <- data$xend %||% data$x
+    data$yend <- data$yend %||% data$y
     data <- check_linewidth(data, snake_class(self))
     data <- remove_missing(data, na.rm = na.rm,
       c("x", "y", "xend", "yend", "linetype", "linewidth", "shape"),
diff --git a/man/geom_segment.Rd b/man/geom_segment.Rd
index fa4781e151..eb3892920b 100644
--- a/man/geom_segment.Rd
+++ b/man/geom_segment.Rd
@@ -125,8 +125,7 @@ need to connect points across multiple cases.
 \itemize{
 \item \strong{\code{\link[=aes_position]{x}}}
 \item \strong{\code{\link[=aes_position]{y}}}
-\item \strong{\code{\link[=aes_position]{xend}}}
-\item \strong{\code{\link[=aes_position]{yend}}}
+\item \strong{\code{\link[=aes_position]{xend}} \emph{or} \code{\link[=aes_position]{yend}}}
 \item \code{\link[=aes_colour_fill_alpha]{alpha}}
 \item \code{\link[=aes_colour_fill_alpha]{colour}}
 \item \code{\link[=aes_group_order]{group}}