diff --git a/apps/referral/__init__.py b/apps/referral/__init__.py
new file mode 100644
index 00000000..e69de29b
diff --git a/apps/referral/apps.py b/apps/referral/apps.py
new file mode 100644
index 00000000..031e3e05
--- /dev/null
+++ b/apps/referral/apps.py
@@ -0,0 +1,10 @@
+# HTK Imports
+from htk.app_config import HtkAppConfig
+
+
+# isort: off
+
+
+class HtkReferralAppConfig(HtkAppConfig):
+    name = 'htk.apps.referral'
+    verbose_name = 'HTK Referral'
diff --git a/apps/referral/constants/__init__.py b/apps/referral/constants/__init__.py
new file mode 100644
index 00000000..e69de29b
diff --git a/apps/referral/constants/defaults.py b/apps/referral/constants/defaults.py
new file mode 100644
index 00000000..e76de5cc
--- /dev/null
+++ b/apps/referral/constants/defaults.py
@@ -0,0 +1,16 @@
+# Referral app settings
+
+# Allow hash referral codes
+HTK_REFERRAL_ALLOW_HASH_CODE = True
+
+# Allow usernames as referral code
+HTK_REFERRAL_ALLOW_USERNAME = True
+
+# Redirect URL name for the referral URL
+HTK_REFERRAL_REDIRECT_URL_NAME = 'home'
+
+HTK_REFERRAL_QUERY_PARAM = 'ref'
+
+HTK_REFERRAL_MODEL = 'htk.Referral'
+
+HTK_REFERRAL_CODE_MODEL = 'htk.ReferralCode'
diff --git a/apps/referral/middleware.py b/apps/referral/middleware.py
new file mode 100644
index 00000000..c3b7f7d5
--- /dev/null
+++ b/apps/referral/middleware.py
@@ -0,0 +1,29 @@
+# Django Imports
+from django.utils.deprecation import MiddlewareMixin
+
+# HTK Imports
+from htk.utils import htk_setting
+
+# Local Imports
+from .utils import get_referrer_from_code
+
+
+# isort: off
+
+
+class ReferralMiddleware(MiddlewareMixin):
+    def __init__(self, *args, **kwargs):
+        super(ReferralMiddleware, self).__init__(*args, **kwargs)
+        self.referrer = None
+
+    def process_request(self, request):
+        key = htk_setting('HTK_REFERRAL_QUERY_PARAM_KEY')
+        referral_code = request.GET.get(key)
+        if referral_code:
+            self.referrer = get_referrer_from_code(referral_code)
+
+    def process_response(self, request, response):
+        if self.referrer:
+            request.session['referrer_id'] = self.referrer.id
+            response.set_cookie('referrer_id', self.referrer.id)
+        return response
diff --git a/apps/referral/models/__init__.py b/apps/referral/models/__init__.py
new file mode 100644
index 00000000..e69de29b
diff --git a/apps/referral/models/referal_code.py b/apps/referral/models/referal_code.py
new file mode 100644
index 00000000..52f5074c
--- /dev/null
+++ b/apps/referral/models/referal_code.py
@@ -0,0 +1,20 @@
+# Django Imports
+from django.conf import settings
+from django.db import models
+
+
+class ReferralCode(models.Model):
+    """Referral Code model"""
+
+    code = models.CharField(max_length=56, unique=True)
+    user = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        related_name='referral_codes',
+        on_delete=models.CASCADE,
+    )
+    created_at = models.DateTimeField(auto_now_add=True)
+    updated_at = models.DateTimeField(auto_now=True)
+
+    class Meta:
+        abstract = True
+        unique_together = ('code',)
diff --git a/apps/referral/models/referral.py b/apps/referral/models/referral.py
new file mode 100644
index 00000000..361fe790
--- /dev/null
+++ b/apps/referral/models/referral.py
@@ -0,0 +1,27 @@
+# Django Imports
+from django.conf import settings
+from django.db import models
+
+
+# isort: off
+
+
+class Referral(models.Model):
+    """Referral model"""
+
+    referrer = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        related_name='referrals',
+        on_delete=models.CASCADE,
+    )
+    referred = models.OneToOneField(
+        settings.AUTH_USER_MODEL,
+        related_name='referred_by',
+        on_delete=models.CASCADE,
+    )
+    created_at = models.DateTimeField(auto_now_add=True)
+    updated_at = models.DateTimeField(auto_now=True)
+
+    class Meta:
+        abstract = True
+        unique_together = ('referrer', 'referred')
diff --git a/apps/referral/resolvers.py b/apps/referral/resolvers.py
new file mode 100644
index 00000000..f021c007
--- /dev/null
+++ b/apps/referral/resolvers.py
@@ -0,0 +1,17 @@
+# Django Imports
+from django.core.exceptions import AppRegistryNotReady
+
+# HTK Imports
+from htk.utils import (
+    htk_setting,
+    resolve_model_dynamically,
+)
+
+
+try:
+    Referral = resolve_model_dynamically(htk_setting('HTK_REFERRAL_MODEL'))
+    ReferralCode = resolve_model_dynamically(
+        htk_setting('HTK_REFERRAL_CODE_MODEL')
+    )
+except (LookupError, AppRegistryNotReady):
+    pass
diff --git a/apps/referral/urls.py b/apps/referral/urls.py
new file mode 100644
index 00000000..a33f43e9
--- /dev/null
+++ b/apps/referral/urls.py
@@ -0,0 +1,18 @@
+# Django Imports
+from django.urls import re_path
+
+# Local Imports
+from . import views
+
+
+# isort: off
+
+
+urlpatterns = [
+    re_path(
+        # if the referral code is prefixed with an '@', it is an username
+        r'^referrals/(?P<referral_code>@?[a-zA-Z0-9_-]+)$',
+        views.referral_view,
+        name='htk_referral',
+    ),
+]
diff --git a/apps/referral/utils.py b/apps/referral/utils.py
new file mode 100644
index 00000000..860eb5bc
--- /dev/null
+++ b/apps/referral/utils.py
@@ -0,0 +1,51 @@
+# Django Imports
+from django.contrib.auth import get_user_model
+
+# HTK Imports
+from htk.utils import htk_setting
+
+# Local Imports
+from .resolvers import ReferralCode
+
+
+# isort: off
+
+
+UserModel = get_user_model()
+
+
+def get_referrer_from_code(referral_code):
+    referrer = None
+    if htk_setting('HTK_REFERRAL_ALLOW_USERNAME') and referral_code.startswith(
+        '@'
+    ):
+        # referral code is an username
+        username = referral_code[1:]
+        try:
+            referrer = UserModel.objects.get(username=username)
+        except UserModel.DoesNotExist:
+            pass
+    elif htk_setting('HTK_REFERRAL_ALLOW_HASH_CODE'):
+        try:
+            referral_code = ReferralCode.objects.get(code=referral_code)
+            referrer = referral_code.user
+        except ReferralCode.DoesNotExist:
+            pass
+    else:
+        raise ValueError(
+            'Either usernames or hash codes must be allowed in referral codes.'
+        )
+    return referrer
+
+
+def get_referrer(request):
+    referrer = None
+    key = 'referrer_id'
+    referrer_id = request.COOKIE.get(key) or request.session.get(key)
+
+    if referrer_id:
+        try:
+            referrer = UserModel.objects.get(id=referrer_id)
+        except UserModel.DoesNotExist:
+            pass
+    return referrer
diff --git a/apps/referral/views.py b/apps/referral/views.py
new file mode 100644
index 00000000..2e244103
--- /dev/null
+++ b/apps/referral/views.py
@@ -0,0 +1,29 @@
+# Django Imports
+from django.contrib.auth import get_user_model
+from django.http import Http404
+from django.shortcuts import redirect
+
+# HTK Imports
+from htk.utils import htk_setting
+
+# Local Imports
+from .utils import get_referrer_from_code
+
+
+# isort: off
+
+
+UserModel = get_user_model()
+
+
+def referral_view(request, referral_code: str, *args, **kwargs):
+    referrer = get_referrer_from_code(referral_code)
+
+    if referrer:
+        request.session['referrer_id'] = referrer.id
+        request.set_cookie('referrer_id', referrer.id)
+        response = redirect(htk_setting('HTK_REFERRAL_REDIRECT_URL'))
+    else:
+        response = Http404
+
+        return response
diff --git a/constants/defaults.py b/constants/defaults.py
index c35aeb8c..eb46bb7d 100644
--- a/constants/defaults.py
+++ b/constants/defaults.py
@@ -102,6 +102,7 @@
 from htk.apps.notifications.constants.defaults import *
 from htk.apps.organizations.constants.defaults import *
 from htk.apps.prelaunch.constants.defaults import *
+from htk.apps.referral.constants.defaults import *
 from htk.cache.constants.defaults import *
 from htk.forms.constants.defaults import *
 from htk.lib.alexa.constants.defaults import *