diff --git a/src/serialize.h b/src/serialize.h
--- a/src/serialize.h
+++ b/src/serialize.h
@@ -703,6 +703,54 @@
     return BigEndian<I>(n);
 }
 
+/**
+ * Formatter to serialize/deserialize vector elements using another formatter
+ *
+ * Example:
+ *   struct X {
+ *     std::vector<uint64_t> v;
+ *     SERIALIZE_METHODS(X, obj) {
+ *       READWRITE(Using<VectorFormatter<VarInt>>(obj.v));
+ *     }
+ *   };
+ * will define a struct that contains a vector of uint64_t, which is serialized
+ * as a vector of VarInt-encoded integers.
+ *
+ * V is not required to be an std::vector type. It works for any class that
+ * exposes a value_type, size, reserve, push_back, and const iterators.
+ */
+template <class Formatter> struct VectorFormatter {
+    template <typename Stream, typename V> void Ser(Stream &s, const V &v) {
+        WriteCompactSize(s, v.size());
+        for (const typename V::value_type &elem : v) {
+            s << Using<Formatter>(elem);
+        }
+    }
+
+    template <typename Stream, typename V> void Unser(Stream &s, V &v) {
+        v.clear();
+        size_t size = ReadCompactSize(s);
+        size_t allocated = 0;
+        while (allocated < size) {
+            // For DoS prevention, do not blindly allocate as much as the stream
+            // claims to contain. Instead, allocate in 5MiB batches, so that an
+            // attacker actually needs to provide X MiB of data to make us
+            // allocate X+5 Mib.
+            static_assert(sizeof(typename V::value_type) <= MAX_VECTOR_ALLOCATE,
+                          "Vector element size too large");
+            allocated =
+                std::min(size, allocated + MAX_VECTOR_ALLOCATE /
+                                               sizeof(typename V::value_type));
+            v.reserve(allocated);
+            while (v.size() < allocated) {
+                typename V::value_type val;
+                s >> Using<Formatter>(val);
+                v.push_back(std::move(val));
+            }
+        }
+    };
+};
+
 /**
  * Forward declarations
  */