diff --git a/ruby/red-arrow/lib/arrow/column.rb b/ruby/red-arrow/lib/arrow/column.rb
index ba575381eefdc..a1de0d61282c2 100644
--- a/ruby/red-arrow/lib/arrow/column.rb
+++ b/ruby/red-arrow/lib/arrow/column.rb
@@ -58,11 +58,11 @@ def reverse_each(&block)
       @data.reverse_each(&block)
     end
 
-    def n_rows
-      @data.n_rows
+    def size
+      @data.size
     end
-    alias_method :size, :n_rows
-    alias_method :length, :n_rows
+    alias_method :length, :size
+    alias_method :n_rows, :size
 
     def n_nulls
       @data.n_nulls
diff --git a/ruby/red-arrow/test/test-column.rb b/ruby/red-arrow/test/test-column.rb
index f78377e363ba4..c3a6ee0f4d34f 100644
--- a/ruby/red-arrow/test/test-column.rb
+++ b/ruby/red-arrow/test/test-column.rb
@@ -49,6 +49,14 @@ def setup
     assert_equal([false, nil, true], @column.reverse_each.to_a)
   end
 
+  test("#size") do
+    assert_equal(3, @column.size)
+  end
+
+  test("#length") do
+    assert_equal(3, @column.length)
+  end
+
   test("#n_rows") do
     assert_equal(3, @column.n_rows)
   end
diff --git a/ruby/red-arrow/test/test-record-batch.rb b/ruby/red-arrow/test/test-record-batch.rb
index e94c26f2e329b..fec640343c60a 100644
--- a/ruby/red-arrow/test/test-record-batch.rb
+++ b/ruby/red-arrow/test/test-record-batch.rb
@@ -178,5 +178,11 @@ def setup
                      @record_batch[[:c, "a", -1, 3..4]])
       end
     end
+
+    sub_test_case("#column") do
+      test("#size") do
+        assert_equal(@counts.size, @record_batch[:count].size)
+      end
+    end
   end
 end