diff --git a/app/services/ldap_service.py b/app/services/ldap_service.py
new file mode 100644
index 0000000..128bfcf
--- /dev/null
+++ b/app/services/ldap_service.py
@@ -0,0 +1,130 @@
+from ldap3 import (
+    Server,
+    Connection,
+    ALL,
+    NTLM,
+    SIMPLE,
+    SUBTREE
+)
+
+from flask import current_app
+from app.config import Config
+
+
+class LDAPService:
+    """
+    LDAP / Active Directory Authentication Service
+    """
+
+    @staticmethod
+    def authenticate(username, password):
+        """
+        Authenticate LDAP User
+
+        Returns:
+            {
+                "success": True,
+                "user": {
+                    "username": "...",
+                    "name": "...",
+                    "email": "..."
+                }
+            }
+
+        OR
+
+            {
+                "success": False,
+                "message": "Invalid username or password"
+            }
+        """
+
+        if not username or not password:
+            return {
+                "success": False,
+                "message": "Username and Password are required."
+            }
+
+        try:
+
+            # -----------------------------------
+            # LDAP SERVER
+            # -----------------------------------
+            server = Server(
+                Config.LDAP_SERVER,
+                port=Config.LDAP_PORT,
+                use_ssl=Config.LDAP_USE_SSL,
+                get_info=ALL
+            )
+
+            # -----------------------------------
+            # Login Format
+            #
+            # username@domain.com
+            # -----------------------------------
+            user_dn = f"{username}@{Config.LDAP_DOMAIN}"
+
+            conn = Connection(
+                server,
+                user=user_dn,
+                password=password,
+                authentication=SIMPLE,
+                auto_bind=True
+            )
+
+            # -----------------------------------
+            # Search User
+            # -----------------------------------
+            search_filter = f"(sAMAccountName={username})"
+
+            conn.search(
+                search_base=Config.LDAP_SEARCH_BASE,
+                search_filter=search_filter,
+                search_scope=SUBTREE,
+                attributes=[
+                    "displayName",
+                    "mail",
+                    "givenName",
+                    "sn",
+                    "cn"
+                ]
+            )
+
+            display_name = username
+            email = ""
+
+            if conn.entries:
+
+                entry = conn.entries[0]
+
+                if "displayName" in entry:
+                    display_name = str(entry.displayName)
+
+                if "mail" in entry:
+                    email = str(entry.mail)
+
+            conn.unbind()
+
+            current_app.logger.info(
+                f"LDAP Login Success : {username}"
+            )
+
+            return {
+                "success": True,
+                "user": {
+                    "username": username,
+                    "name": display_name,
+                    "email": email
+                }
+            }
+
+        except Exception as ex:
+
+            current_app.logger.warning(
+                f"LDAP Login Failed : {username} : {str(ex)}"
+            )
+
+            return {
+                "success": False,
+                "message": "Invalid Username or Password."
+            }
\ No newline at end of file