diff --git a/instrumentation/active_support/README.md b/instrumentation/active_support/README.md
index 04235ba739..64857f0c65 100644
--- a/instrumentation/active_support/README.md
+++ b/instrumentation/active_support/README.md
@@ -1,4 +1,5 @@
 # OpenTelemetry ActiveSupport Instrumentation
+
 The Active Support instrumentation is a community-maintained instrumentation for the Active Support portion of the [Ruby on Rails][rails-home] web-application framework.
 
 ## How do I get started?
diff --git a/instrumentation/active_support/lib/opentelemetry/instrumentation/active_support/span_subscriber.rb b/instrumentation/active_support/lib/opentelemetry/instrumentation/active_support/span_subscriber.rb
index 41efeb94a0..e11a80fa43 100644
--- a/instrumentation/active_support/lib/opentelemetry/instrumentation/active_support/span_subscriber.rb
+++ b/instrumentation/active_support/lib/opentelemetry/instrumentation/active_support/span_subscriber.rb
@@ -8,6 +8,8 @@ module OpenTelemetry
   module Instrumentation
     # rubocop:disable Style/Documentation
     module ActiveSupport
+      LEGACY_NAME_FORMATTER = ->(name) { name.split('.')[0..1].reverse.join(' ').freeze }
+
       # The SpanSubscriber is a special ActiveSupport::Notification subscription
       # handler which turns notifications into generic spans, taking care to handle
       # context appropriately.
@@ -20,11 +22,13 @@ def self.subscribe(
         pattern,
         notification_payload_transform = nil,
         disallowed_notification_payload_keys = [],
-        kind = nil
+        kind = nil,
+        span_name_formatter = nil
       )
         subscriber = OpenTelemetry::Instrumentation::ActiveSupport::SpanSubscriber.new(
           name: pattern,
           tracer: tracer,
+          span_name_formatter: span_name_formatter,
           notification_payload_transform: notification_payload_transform,
           disallowed_notification_payload_keys: disallowed_notification_payload_keys,
           kind: nil
@@ -58,7 +62,7 @@ class SpanSubscriber
         ALWAYS_VALID_PAYLOAD_TYPES = [TrueClass, FalseClass, String, Numeric, Symbol].freeze
 
         def initialize(name:, tracer:, notification_payload_transform: nil, disallowed_notification_payload_keys: [], kind: nil)
-          @span_name = name.split('.')[0..1].reverse.join(' ').freeze
+          @span_name = safe_span_name_for(span_name_formatter, name)
           @tracer = tracer
           @notification_payload_transform = notification_payload_transform
           @disallowed_notification_payload_keys = disallowed_notification_payload_keys
@@ -128,6 +132,16 @@ def sanitized_value(value)
             value
           end
         end
+
+        # Helper method to try an shield the span name formatter from errors
+        #
+        # It wraps the user supplied formatter in a rescue block and returns the original name if a StandardError is raised by the formatter
+        def safe_span_name_for(span_name_formatter, name)
+          span_name_formatter&.call(name) || name
+        rescue StandardError => e
+          OpenTelemetry.handle_error(exception: e, message: 'Error calling span_name_formatter. Using default span name.')
+          name
+        end
       end
     end
   end
diff --git a/instrumentation/active_support/opentelemetry-instrumentation-active_support.gemspec b/instrumentation/active_support/opentelemetry-instrumentation-active_support.gemspec
index 8b6b68faf4..30201b7d61 100644
--- a/instrumentation/active_support/opentelemetry-instrumentation-active_support.gemspec
+++ b/instrumentation/active_support/opentelemetry-instrumentation-active_support.gemspec
@@ -38,6 +38,7 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'pry-byebug'
   spec.add_development_dependency 'rails', '>= 6.1'
   spec.add_development_dependency 'rake', '~> 13.0'
+  spec.add_development_dependency 'rspec-mocks'
   spec.add_development_dependency 'rubocop', '~> 1.64.0'
   spec.add_development_dependency 'rubocop-performance', '~> 1.20'
   spec.add_development_dependency 'simplecov', '~> 0.17.1'
diff --git a/instrumentation/active_support/test/opentelemetry/instrumentation/active_support/span_subscriber_test.rb b/instrumentation/active_support/test/opentelemetry/instrumentation/active_support/span_subscriber_test.rb
index 4b6b596d72..98f5fdfcf9 100644
--- a/instrumentation/active_support/test/opentelemetry/instrumentation/active_support/span_subscriber_test.rb
+++ b/instrumentation/active_support/test/opentelemetry/instrumentation/active_support/span_subscriber_test.rb
@@ -12,9 +12,10 @@
   let(:exporter) { EXPORTER }
   let(:last_span) { exporter.finished_spans.last }
   let(:span_kind) { nil }
+  let(:notification_name) { 'bar.foo' }
   let(:subscriber) do
     OpenTelemetry::Instrumentation::ActiveSupport::SpanSubscriber.new(
-      name: 'bar.foo',
+      name: notification_name,
       tracer: tracer,
       kind: span_kind
     )
@@ -36,7 +37,7 @@ def finish(name, id, payload)
 
   it 'memoizes the span name' do
     span, = subscriber.start('oh.hai', 'abc', {})
-    _(span.name).must_equal('foo bar')
+    _(span.name).must_equal(notification_name)
   end
 
   it 'uses the provided tracer' do
@@ -115,7 +116,7 @@ def finish(name, id, payload)
   describe 'instrumentation option - disallowed_notification_payload_keys' do
     let(:subscriber) do
       OpenTelemetry::Instrumentation::ActiveSupport::SpanSubscriber.new(
-        name: 'bar.foo',
+        name: notification_name,
         tracer: tracer,
         notification_payload_transform: nil,
         disallowed_notification_payload_keys: [:foo]
@@ -153,7 +154,7 @@ def finish(name, id, payload)
     let(:transformer_proc) { ->(v) { v.transform_values { 'optimus prime' } } }
     let(:subscriber) do
       OpenTelemetry::Instrumentation::ActiveSupport::SpanSubscriber.new(
-        name: 'bar.foo',
+        name: notification_name,
         tracer: tracer,
         notification_payload_transform: transformer_proc,
         disallowed_notification_payload_keys: [:foo]
@@ -205,57 +206,105 @@ def finish(name, id, payload)
 
   describe 'instrument' do
     before do
-      ActiveSupport::Notifications.unsubscribe('bar.foo')
+      ActiveSupport::Notifications.unsubscribe(notification_name)
     end
 
     it 'does not trace an event by default' do
-      ActiveSupport::Notifications.subscribe('bar.foo') do
+      ActiveSupport::Notifications.subscribe(notification_name) do
         # pass
       end
-      ActiveSupport::Notifications.instrument('bar.foo', extra: 'context')
+      ActiveSupport::Notifications.instrument(notification_name, extra: 'context')
       _(last_span).must_be_nil
     end
 
     it 'traces an event when a span subscriber is used' do
-      OpenTelemetry::Instrumentation::ActiveSupport.subscribe(tracer, 'bar.foo')
-      ActiveSupport::Notifications.instrument('bar.foo', extra: 'context')
+      OpenTelemetry::Instrumentation::ActiveSupport.subscribe(tracer, notification_name)
+      ActiveSupport::Notifications.instrument(notification_name, extra: 'context')
 
       _(last_span).wont_be_nil
-      _(last_span.name).must_equal('foo bar')
+      _(last_span.name).must_equal(notification_name)
       _(last_span.attributes['extra']).must_equal('context')
     end
 
+    describe 'when using a custom span name formatter' do
+      describe 'when using the LEGACY_NAME_FORATTER' do
+        it 'uses the user supplied formatter' do
+          OpenTelemetry::Instrumentation::ActiveSupport.subscribe(tracer, notification_name, nil, nil, OpenTelemetry::Instrumentation::ActiveSupport::LEGACY_NAME_FORMATTER)
+          ActiveSupport::Notifications.instrument(notification_name, extra: 'context')
+
+          _(last_span).wont_be_nil
+          _(last_span.name).must_equal('foo bar')
+          _(last_span.attributes['extra']).must_equal('context')
+        end
+      end
+
+      describe 'when using a custom formatter' do
+        it 'uses the user supplied formatter' do
+          OpenTelemetry::Instrumentation::ActiveSupport.subscribe(tracer, notification_name, nil, nil, ->(name) { "custom.#{name}" })
+          ActiveSupport::Notifications.instrument(notification_name, extra: 'context')
+
+          _(last_span).wont_be_nil
+          _(last_span.name).must_equal('custom.bar.foo')
+          _(last_span.attributes['extra']).must_equal('context')
+        end
+      end
+
+      describe 'when using a invalid formatter' do
+        it 'defaults to the notification name' do
+          OpenTelemetry::Instrumentation::ActiveSupport.subscribe(tracer, notification_name, nil, nil, ->(_) {})
+          ActiveSupport::Notifications.instrument(notification_name, extra: 'context')
+
+          _(last_span).wont_be_nil
+          _(last_span.name).must_equal(notification_name)
+          _(last_span.attributes['extra']).must_equal('context')
+        end
+      end
+
+      describe 'when using a unstable formatter' do
+        it 'defaults to the notification name' do
+          allow(OpenTelemetry).to receive(:handle_error).with(exception: RuntimeError, message: String)
+
+          OpenTelemetry::Instrumentation::ActiveSupport.subscribe(tracer, notification_name, nil, nil, ->(_) { raise 'boom' })
+          ActiveSupport::Notifications.instrument(notification_name, extra: 'context')
+
+          _(last_span).wont_be_nil
+          _(last_span.name).must_equal(notification_name)
+          _(last_span.attributes['extra']).must_equal('context')
+        end
+      end
+    end
+
     it 'finishes spans even when block subscribers blow up' do
-      ActiveSupport::Notifications.subscribe('bar.foo') { raise 'boom' }
-      OpenTelemetry::Instrumentation::ActiveSupport.subscribe(tracer, 'bar.foo')
+      ActiveSupport::Notifications.subscribe(notification_name) { raise 'boom' }
+      OpenTelemetry::Instrumentation::ActiveSupport.subscribe(tracer, notification_name)
 
       expect do
-        ActiveSupport::Notifications.instrument('bar.foo', extra: 'context')
+        ActiveSupport::Notifications.instrument(notification_name, extra: 'context')
       end.must_raise RuntimeError
 
       _(last_span).wont_be_nil
-      _(last_span.name).must_equal('foo bar')
+      _(last_span.name).must_equal(notification_name)
       _(last_span.attributes['extra']).must_equal('context')
     end
 
     it 'finishes spans even when complex subscribers blow up' do
-      ActiveSupport::Notifications.subscribe('bar.foo', CrashingEndSubscriber.new)
-      OpenTelemetry::Instrumentation::ActiveSupport.subscribe(tracer, 'bar.foo')
+      ActiveSupport::Notifications.subscribe(notification_name, CrashingEndSubscriber.new)
+      OpenTelemetry::Instrumentation::ActiveSupport.subscribe(tracer, notification_name)
 
       expect do
-        ActiveSupport::Notifications.instrument('bar.foo', extra: 'context')
+        ActiveSupport::Notifications.instrument(notification_name, extra: 'context')
       end.must_raise RuntimeError
 
       _(last_span).wont_be_nil
-      _(last_span.name).must_equal('foo bar')
+      _(last_span.name).must_equal(notification_name)
       _(last_span.attributes['extra']).must_equal('context')
     end
 
     it 'supports unsubscribe' do
-      obj = OpenTelemetry::Instrumentation::ActiveSupport.subscribe(tracer, 'bar.foo')
+      obj = OpenTelemetry::Instrumentation::ActiveSupport.subscribe(tracer, notification_name)
       ActiveSupport::Notifications.unsubscribe(obj)
 
-      ActiveSupport::Notifications.instrument('bar.foo', extra: 'context')
+      ActiveSupport::Notifications.instrument(notification_name, extra: 'context')
 
       _(obj.class).must_equal(ActiveSupport::Notifications::Fanout::Subscribers::Evented)
       _(last_span).must_be_nil
diff --git a/instrumentation/active_support/test/test_helper.rb b/instrumentation/active_support/test/test_helper.rb
index 011abee7b0..2c5c5cce28 100644
--- a/instrumentation/active_support/test/test_helper.rb
+++ b/instrumentation/active_support/test/test_helper.rb
@@ -12,6 +12,7 @@
 require 'opentelemetry-instrumentation-active_support'
 
 require 'minitest/autorun'
+require 'rspec/mocks/minitest_integration'
 require 'webmock/minitest'
 
 # global opentelemetry-sdk setup: