From 425a73efbd4d9c0c06012350035b5a2b8c1ef7d0 Mon Sep 17 00:00:00 2001
From: Davis Vaughan <davis@posit.co>
Date: Mon, 5 Jan 2026 22:00:00 -0500
Subject: [PATCH 1/2] Remove old `add =` tests

---
 r/tests/testthat/test-dplyr-group-by.R | 32 --------------------------
 1 file changed, 32 deletions(-)

diff --git a/r/tests/testthat/test-dplyr-group-by.R b/r/tests/testthat/test-dplyr-group-by.R
index 30a727ed073..c3527f25650 100644
--- a/r/tests/testthat/test-dplyr-group-by.R
+++ b/r/tests/testthat/test-dplyr-group-by.R
@@ -271,38 +271,6 @@ test_that("group_by() with .add", {
     tbl |>
       group_by(dbl2)
   )
-  suppressWarnings(compare_dplyr_binding(
-    .input |>
-      group_by(dbl2) |>
-      group_by(add = FALSE) |>
-      collect(),
-    tbl,
-    warning = "deprecated"
-  ))
-  suppressWarnings(compare_dplyr_binding(
-    .input |>
-      group_by(dbl2) |>
-      group_by(add = TRUE) |>
-      collect(),
-    tbl,
-    warning = "deprecated"
-  ))
-  expect_warning(
-    tbl |>
-      arrow_table() |>
-      group_by(add = TRUE) |>
-      collect(),
-    "The `add` argument of `group_by\\(\\)` is deprecated"
-  )
-  expect_error(
-    suppressWarnings(
-      tbl |>
-        arrow_table() |>
-        group_by(add = dbl2) |>
-        collect()
-    ),
-    "object 'dbl2' not found"
-  )
 })
 
 test_that("Can use across() within group_by()", {

From 733f18e87dc5cf4eebd97330faa1710ddd17ba22 Mon Sep 17 00:00:00 2001
From: Davis Vaughan <davis@posit.co>
Date: Wed, 7 Jan 2026 13:09:31 -0500
Subject: [PATCH 2/2] Remove `add` from `group_by()` methods

---
 r/R/dplyr-group-by.R | 11 -----------
 1 file changed, 11 deletions(-)

diff --git a/r/R/dplyr-group-by.R b/r/R/dplyr-group-by.R
index 26da312e4b7..268bf064af1 100644
--- a/r/R/dplyr-group-by.R
+++ b/r/R/dplyr-group-by.R
@@ -21,19 +21,8 @@ group_by.arrow_dplyr_query <- function(
   .data,
   ...,
   .add = FALSE,
-  add = NULL,
   .drop = dplyr::group_by_drop_default(.data)
 ) {
-  if (!missing(add)) {
-    .Deprecated(
-      msg = paste(
-        "The `add` argument of `group_by()` is deprecated.",
-        "Please use the `.add` argument instead."
-      )
-    )
-    .add <- add
-  }
-
   .data <- as_adq(.data)
   expression_list <- expand_across(.data, quos(...))
   named_expression_list <- ensure_named_exprs(expression_list)