diff --git a/base/ctf/cicero/cicfifo.h b/base/ctf/cicero/cicfifo.h
new file mode 100644
index 00000000000..4bb48fcc37b
--- /dev/null
+++ b/base/ctf/cicero/cicfifo.h
@@ -0,0 +1,122 @@
+/*
+ * PROJECT:     ReactOS Cicero
+ * LICENSE:     LGPL-2.1-or-later (https://spdx.org/licenses/LGPL-2.1-or-later)
+ * PURPOSE:     Cicero FIFO (First-In-First-Out)
+ * COPYRIGHT:   Copyright 2026 Katayama Hirofumi MZ <katayama.hirofumi.mz@gmail.com>
+ */
+
+#pragma once
+
+#include "cicbase.h"
+
+// FIFO (First-In-First-Out) ring buffer
+template <typename T_ITEM>
+class CicFirstInFirstOut
+{
+protected:
+    T_ITEM* m_pItems;
+    size_t m_cItems;
+    size_t m_iBack;
+    size_t m_iFront;
+    //static_assert(std::is_trivially_copyable<T_ITEM>::value, ""); // FIXME
+
+public:
+    CicFirstInFirstOut(size_t cInitial = 0)
+        : m_pItems(NULL)
+        , m_cItems(0)
+        , m_iBack(0)
+        , m_iFront(0)
+    {
+        if (cInitial)
+            GrowBuffer(cInitial);
+    }
+
+    ~CicFirstInFirstOut()
+    {
+        cicMemFree(m_pItems);
+    }
+
+    size_t GetSize() const
+    {
+        if (m_iBack == m_iFront)
+            return 0;
+        if (m_iBack < m_iFront)
+            return m_iBack + (m_cItems - m_iFront);
+        return m_iBack - m_iFront;
+    }
+
+    // Like push_back
+    BOOL SetData(const T_ITEM* pItem)
+    {
+        if (!m_cItems || GetSize() + 1 >= m_cItems) /* "+1" is for marking */
+        {
+            if (!GrowBuffer(!m_cItems ? 8 : m_cItems))
+                return FALSE;
+        }
+
+        m_pItems[m_iBack] = *pItem;
+
+        if (++m_iBack == m_cItems)
+            m_iBack = 0;
+
+        return TRUE;
+    }
+
+    // Like front and pop_front
+    BOOL GetData(T_ITEM* pItem)
+    {
+        if (m_iFront == m_iBack)
+            return FALSE;
+        *pItem = m_pItems[m_iFront];
+        if (++m_iFront == m_cItems)
+            m_iFront = 0;
+        return TRUE;
+    }
+
+protected:
+    BOOL GrowBuffer(size_t nGrow)
+    {
+        if (nGrow == 0)
+            return TRUE;
+
+        if (!m_pItems)
+        {
+            m_pItems = (T_ITEM*)cicMemAlloc(nGrow * sizeof(T_ITEM));
+            if (m_pItems)
+                m_cItems = nGrow;
+            return !!m_pItems;
+        }
+
+        size_t cNewItems = m_cItems + nGrow;
+        if (cNewItems < m_cItems || cNewItems > ~(size_t)0 / sizeof(T_ITEM))
+            return FALSE;
+
+        T_ITEM* pNewItems = (T_ITEM*)cicMemAlloc(cNewItems * sizeof(T_ITEM));
+        if (!pNewItems)
+            return FALSE;
+
+        if (m_iBack < m_iFront)
+        {
+            size_t cTail = m_cItems - m_iFront;
+            CopyMemory(pNewItems, &m_pItems[m_iFront], cTail * sizeof(T_ITEM));
+            CopyMemory(&pNewItems[cTail], m_pItems, m_iBack * sizeof(T_ITEM));
+            m_iBack = cTail + m_iBack;
+        }
+        else
+        {
+            size_t nCount = m_iBack - m_iFront;
+            CopyMemory(pNewItems, &m_pItems[m_iFront], nCount * sizeof(T_ITEM));
+            m_iBack = nCount;
+        }
+        m_iFront = 0;
+
+        cicMemFree(m_pItems);
+        m_pItems = pNewItems;
+        m_cItems = cNewItems;
+        return TRUE;
+    }
+
+private:
+    CicFirstInFirstOut(const CicFirstInFirstOut&) = delete;
+    CicFirstInFirstOut& operator=(const CicFirstInFirstOut&) = delete;
+};