diff --git a/CMakeLists.txt b/CMakeLists.txt
index d37aae8a4..1b4bbde03 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -206,6 +206,8 @@ configure_file(${CMAKE_CURRENT_SOURCE_DIR}/python/__version__.py.in
 install(FILES ${CMAKE_CURRENT_SOURCE_DIR}/LICENSE
         DESTINATION ${CMAKE_INSTALL_DOCDIR})
 
+find_package(fmt 9 REQUIRED)
+
 #--- project specific subdirectories -------------------------------------------
 add_subdirectory(src)
 
@@ -222,8 +224,6 @@ if(BUILD_TESTING)
   add_subdirectory(tests)
 endif()
 
-find_package(fmt 9 REQUIRED)
-
 add_subdirectory(tools)
 add_subdirectory(python)
 
diff --git a/cmake/podioConfig.cmake.in b/cmake/podioConfig.cmake.in
index 674602faa..b2d20c9e4 100644
--- a/cmake/podioConfig.cmake.in
+++ b/cmake/podioConfig.cmake.in
@@ -30,6 +30,7 @@ if(NOT "@REQUIRE_PYTHON_VERSION@" STREQUAL "")
 else()
   find_dependency(Python3 COMPONENTS Interpreter Development)
 endif()
+find_dependency(fmt @fmt_VERSION@)
 
 SET(PODIO_ENABLE_SIO @ENABLE_SIO@)
 if(PODIO_ENABLE_SIO)
diff --git a/include/podio/ObjectID.h b/include/podio/ObjectID.h
index 02efc48df..0dbf0e7cd 100644
--- a/include/podio/ObjectID.h
+++ b/include/podio/ObjectID.h
@@ -1,6 +1,12 @@
 #ifndef PODIO_OBJECTID_H
 #define PODIO_OBJECTID_H
 
+// Hide the fmt dependency from cling, so that ROOT does not need to be able to
+// find the fmt headers when it parses the podio headers at runtime
+#if !defined(__CLING__)
+  #include <fmt/ostream.h>
+#endif
+
 #include <compare>
 #include <cstdint>
 #include <functional>
@@ -66,4 +72,9 @@ struct std::hash<podio::ObjectID> {
   }
 };
 
+#if !defined(__CLING__)
+template <>
+struct fmt::formatter<podio::ObjectID> : fmt::ostream_formatter {};
+#endif
+
 #endif
diff --git a/include/podio/UserDataCollection.h b/include/podio/UserDataCollection.h
index 361bb0034..d74aaa20f 100644
--- a/include/podio/UserDataCollection.h
+++ b/include/podio/UserDataCollection.h
@@ -8,6 +8,12 @@
 #include "podio/detail/Pythonizations.h"
 #include "podio/utilities/TypeHelpers.h"
 
+// Hide the fmt dependency from cling, so that ROOT does not need to be able to
+// find the fmt headers when it parses the podio headers at runtime
+#if !defined(__CLING__)
+  #include <fmt/ostream.h>
+#endif
+
 #define PODIO_ADD_USER_TYPE(type)                                                                                      \
   template <>                                                                                                          \
   consteval const char* userDataTypeName<type>() {                                                                     \
@@ -354,4 +360,9 @@ constexpr std::string_view UserDataCollection<BasicType, U>::dataTypeName;
 
 } // namespace podio
 
+#if !defined(__CLING__)
+template <typename BasicType>
+struct fmt::formatter<podio::UserDataCollection<BasicType>> : fmt::ostream_formatter {};
+#endif
+
 #endif
diff --git a/include/podio/detail/Link.h b/include/podio/detail/Link.h
index 9193f80c1..98666dffd 100644
--- a/include/podio/detail/Link.h
+++ b/include/podio/detail/Link.h
@@ -12,6 +12,12 @@
   #include "nlohmann/json.hpp"
 #endif
 
+// Hide the fmt dependency from cling, so that ROOT does not need to be able to
+// find the fmt headers when it parses the podio headers at runtime
+#if !defined(__CLING__)
+  #include <fmt/ostream.h>
+#endif
+
 #include <functional>
 #include <ostream>
 #include <type_traits>
@@ -348,8 +354,8 @@ class LinkT {
   podio::utils::MaybeSharedPtr<LinkObjT> m_obj{nullptr};
 };
 
-template <typename FromT, typename ToT>
-std::ostream& operator<<(std::ostream& os, const Link<FromT, ToT>& link) {
+template <typename FromT, typename ToT, bool Mutable>
+std::ostream& operator<<(std::ostream& os, const LinkT<FromT, ToT, Mutable>& link) {
   if (!link.isAvailable()) {
     return os << "[not available]";
   }
@@ -382,4 +388,9 @@ struct std::hash<podio::LinkT<FromT, ToT, Mutable>> {
   }
 };
 
+#if !defined(__CLING__)
+template <typename FromT, typename ToT, bool Mutable>
+struct fmt::formatter<podio::LinkT<FromT, ToT, Mutable>> : fmt::ostream_formatter {};
+#endif
+
 #endif // PODIO_DETAIL_LINK_H
diff --git a/include/podio/detail/LinkCollectionImpl.h b/include/podio/detail/LinkCollectionImpl.h
index cf498c31d..ee2564118 100644
--- a/include/podio/detail/LinkCollectionImpl.h
+++ b/include/podio/detail/LinkCollectionImpl.h
@@ -28,6 +28,12 @@
   #include "nlohmann/json.hpp"
 #endif
 
+// Hide the fmt dependency from cling, so that ROOT does not need to be able to
+// find the fmt headers when it parses the podio headers at runtime
+#if !defined(__CLING__)
+  #include <fmt/ostream.h>
+#endif
+
 #include <iomanip>
 #include <memory>
 #include <mutex>
@@ -463,4 +469,9 @@ void to_json(nlohmann::json& j, const podio::LinkCollection<FromT, ToT>& collect
 
 } // namespace podio
 
+#if !defined(__CLING__)
+template <typename FromT, typename ToT>
+struct fmt::formatter<podio::LinkCollection<FromT, ToT>> : fmt::ostream_formatter {};
+#endif
+
 #endif // PODIO_DETAIL_LINKCOLLECTIONIMPL_H
diff --git a/python/templates/Collection.h.jinja2 b/python/templates/Collection.h.jinja2
index c74a50d5c..453f18584 100644
--- a/python/templates/Collection.h.jinja2
+++ b/python/templates/Collection.h.jinja2
@@ -30,6 +30,12 @@
 #include <memory>
 #include <cstddef>
 
+// Hide the fmt dependency from cling, so that ROOT does not need to be able to
+// find the fmt headers when it parses the podio headers at runtime
+#if !defined(__CLING__)
+#include <fmt/ostream.h>
+#endif
+
 namespace podio {
   struct RelationNames;
 }
@@ -280,6 +286,11 @@ void to_json(nlohmann::json& j, const {{ class.bare_type }}Collection& collectio
 
 {{ utils.namespace_close(class.namespace) }}
 
+#if !defined(__CLING__)
+template <>
+struct fmt::formatter<{% if class.namespace %}{{ class.namespace }}::{% endif %}{{ class.bare_type }}Collection> : fmt::ostream_formatter {};
+#endif
+
 {{ workarounds.ld_library_path(class, "Collection", ["valueTypeName", "dataTypeName"]) }}
 
 #endif
diff --git a/python/templates/Component.h.jinja2 b/python/templates/Component.h.jinja2
index 19a9e7b8b..ad93170d9 100644
--- a/python/templates/Component.h.jinja2
+++ b/python/templates/Component.h.jinja2
@@ -11,6 +11,12 @@
 {% if generate_current_version %}
 #include <ostream>
 
+// Hide the fmt dependency from cling, so that ROOT does not need to be able to
+// find the fmt headers when it parses the podio headers at runtime
+#if !defined(__CLING__)
+#include <fmt/ostream.h>
+#endif
+
 #if defined(PODIO_JSON_OUTPUT) && !defined(__CLING__)
 #include "nlohmann/json_fwd.hpp"
 #endif
@@ -58,4 +64,11 @@ public:
 
 {{ utils.namespace_close(class.namespace) }}
 
+{% if generate_current_version %}
+#if !defined(__CLING__)
+template <>
+struct fmt::formatter<{{ class.full_type }}> : fmt::ostream_formatter {};
+#endif
+{% endif %}
+
 #endif
diff --git a/python/templates/Interface.h.jinja2 b/python/templates/Interface.h.jinja2
index b23fb1408..c5b13b014 100644
--- a/python/templates/Interface.h.jinja2
+++ b/python/templates/Interface.h.jinja2
@@ -14,6 +14,12 @@
 #include "podio/utilities/TypeHelpers.h"
 #include "podio/detail/OrderKey.h"
 
+// Hide the fmt dependency from cling, so that ROOT does not need to be able to
+// find the fmt headers when it parses the podio headers at runtime
+#if !defined(__CLING__)
+#include <fmt/ostream.h>
+#endif
+
 #include <memory>
 #include <ostream>
 #include <stdexcept>
@@ -190,4 +196,9 @@ struct std::hash<{{ class.full_type }}> {
   }
 };
 
+#if !defined(__CLING__)
+template <>
+struct fmt::formatter<{{ class.full_type }}> : fmt::ostream_formatter {};
+#endif
+
 #endif
diff --git a/python/templates/MutableObject.h.jinja2 b/python/templates/MutableObject.h.jinja2
index ecb9ca5af..87b61dbfb 100644
--- a/python/templates/MutableObject.h.jinja2
+++ b/python/templates/MutableObject.h.jinja2
@@ -62,4 +62,7 @@ private:
 
 {{ macros.std_hash(class, prefix='Mutable') }}
 
+{{ macros.ostream_formatter(class, prefix='Mutable') }}
+
+
 #endif
diff --git a/python/templates/Object.h.jinja2 b/python/templates/Object.h.jinja2
index 9c77afd4d..c2d51ccd6 100644
--- a/python/templates/Object.h.jinja2
+++ b/python/templates/Object.h.jinja2
@@ -15,6 +15,12 @@
 #include "podio/utilities/MaybeSharedPtr.h"
 #include "podio/detail/OrderKey.h"
 
+// Hide the fmt dependency from cling, so that ROOT does not need to be able to
+// find the fmt headers when it parses the podio headers at runtime
+#if !defined(__CLING__)
+#include <fmt/ostream.h>
+#endif
+
 #include <ostream>
 #include <cstdint>
 
@@ -79,6 +85,8 @@ std::ostream& operator<<(std::ostream& o, const {{ class.bare_type }}& value);
 
 {{ macros.std_hash(class) }}
 
+{{ macros.ostream_formatter(class) }}
+
 {{ workarounds.ld_library_path(class) }}
 
 #endif
diff --git a/python/templates/macros/declarations.jinja2 b/python/templates/macros/declarations.jinja2
index 75058f5bc..5f9df0fd5 100644
--- a/python/templates/macros/declarations.jinja2
+++ b/python/templates/macros/declarations.jinja2
@@ -153,3 +153,11 @@ struct std::hash<{{ namespace }}{{ prefix }}{{ class.bare_type }}> {
   }
 };
 {% endmacro %}
+
+{% macro ostream_formatter(class, prefix='') %}
+{% set namespace = class.namespace + '::' if class.namespace else '' %}
+#if !defined(__CLING__)
+template <>
+struct fmt::formatter<{{ namespace }}{{ prefix }}{{ class.bare_type }}> : fmt::ostream_formatter {};
+#endif
+{% endmacro %}
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 3a52679c4..966c623be 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -79,6 +79,7 @@ SET(core_headers
 PODIO_ADD_LIB_AND_DICT(podio "${core_headers}" "${core_sources}" selection.xml)
 target_compile_options(podio PRIVATE -pthread)
 target_link_libraries(podio PRIVATE Python3::Python)
+target_link_libraries(podio PUBLIC fmt::fmt)
 # For Frame.h
 if (ROOT_VERSION VERSION_LESS 6.36)
   target_compile_definitions(podio PUBLIC PODIO_ROOT_OLDER_6_36=1)
diff --git a/tests/unittests/interface_types.cpp b/tests/unittests/interface_types.cpp
index 235456b1e..c756ddff7 100644
--- a/tests/unittests/interface_types.cpp
+++ b/tests/unittests/interface_types.cpp
@@ -219,3 +219,14 @@ TEST_CASE("InterfaceType extension model", "[interface-types][extension]") {
   REQUIRE(wrapper.isA<iextension::AnotherHit>());
   REQUIRE(wrapper.as<iextension::AnotherHit>().energy() == 4.2f);
 }
+
+TEST_CASE("InterfaceType formatting", "[interface-types][basics][formatting]") {
+  auto iface = iextension::EnergyInterface::makeEmpty();
+  auto formatted = fmt::format("{}", iface);
+  REQUIRE(formatted == "[not available]");
+
+  iface = ExampleCluster{};
+  formatted = fmt::format("{}", iface);
+  REQUIRE_FALSE(formatted.empty());
+  REQUIRE(formatted != "[not available]");
+}
diff --git a/tests/unittests/links.cpp b/tests/unittests/links.cpp
index fd76eaed6..ee7f9680b 100644
--- a/tests/unittests/links.cpp
+++ b/tests/unittests/links.cpp
@@ -15,6 +15,8 @@
   #include "nlohmann/json.hpp"
 #endif
 
+#include <fmt/format.h>
+
 #include <map>
 #include <set>
 #include <type_traits>
@@ -305,6 +307,22 @@ TEST_CASE("Links templated accessors", "[links]") {
   }
 }
 // NOLINTEND(clang-analyzer-cplusplus.NewDeleteLeaks)
+
+TEST_CASE("Link formatting", "[links]") {
+  TestL link;
+  auto formatted = fmt::format("{}", link);
+  REQUIRE_FALSE(formatted.empty());
+  REQUIRE(formatted != "[not available]");
+
+  auto emptyLink = TestL::makeEmpty();
+  auto emptyFmt = fmt::format("{}", emptyLink);
+  REQUIRE(emptyFmt == "[not available]");
+
+  TestMutL mutLink;
+  formatted = fmt::format("{}", mutLink);
+  REQUIRE(formatted != "[not avialable]");
+}
+
 TEST_CASE("LinkCollection collection concept", "[links][concepts]") {
   STATIC_REQUIRE(podio::CollectionType<TestLColl>);
   STATIC_REQUIRE(std::is_same_v<std::ranges::range_value_t<TestLColl>, TestL>);
@@ -449,6 +467,19 @@ TEST_CASE("LinkCollection basics", "[links]") {
   }
 }
 
+TEST_CASE("LinkCollection formatting", "[links][formatting]") {
+  podio::LinkCollection<ExampleHit, ExampleCluster> links;
+
+  auto formatted = fmt::format("{}", links);
+  REQUIRE_FALSE(formatted.empty());
+
+  links.create();
+  links.create();
+
+  auto formatted2 = fmt::format("{}", links);
+  REQUIRE(formatted2.size() > formatted.size());
+}
+
 auto createLinkCollections(const size_t nElements = 3u) {
   auto colls = std::make_tuple(TestLColl(), ExampleHitCollection(), ExampleClusterCollection());
 
diff --git a/tests/unittests/unittest.cpp b/tests/unittests/unittest.cpp
index 92fea37f3..35099bf60 100644
--- a/tests/unittests/unittest.cpp
+++ b/tests/unittests/unittest.cpp
@@ -20,6 +20,7 @@
 // podio specific includes
 #include "podio/Frame.h"
 #include "podio/GenericParameters.h"
+#include "podio/ObjectID.h"
 #include "podio/ROOTLegacyReader.h"
 #include "podio/ROOTReader.h"
 #include "podio/ROOTWriter.h"
@@ -60,12 +61,26 @@
 #include "datamodel/MutableExampleWithArray.h"
 #include "datamodel/MutableExampleWithComponent.h"
 #include "datamodel/MutableExampleWithExternalExtraCode.h"
+#include "datamodel/NamespaceInNamespaceStruct.h"
 #include "datamodel/StructWithExtraCode.h"
 #include "datamodel/datamodel.h"
 #include "extension_model/extension_model.h"
 
 #include "podio/UserDataCollection.h"
 
+#include <fmt/format.h>
+
+TEST_CASE("ObjectID formatting", "[basics][formatting]") {
+  auto objId = podio::ObjectID{};
+  auto formatted = fmt::format("{}", objId);
+  REQUIRE(formatted == "ffffffff|-1");
+
+  objId.collectionID = 42;
+  objId.index = 123;
+  formatted = fmt::format("{}", objId);
+  REQUIRE(formatted == fmt::format("{:8x}|123", 42));
+}
+
 TEST_CASE("AutoDelete", "[basics][memory-management]") {
   auto coll = EventInfoCollection();
   auto hit1 = MutableEventInfo();
@@ -138,6 +153,30 @@ TEST_CASE("makeEmpty", "[basics]") {
   REQUIRE(hit.energy() == 0);
 }
 
+TEST_CASE("Object formatting", "[basics][formatting]") {
+  ExampleCluster cluster;
+  auto formatted = fmt::format("{}", cluster);
+  REQUIRE_FALSE(formatted.empty());
+  REQUIRE(formatted != "[not avaialble]");
+
+  cluster = ExampleCluster::makeEmpty();
+  formatted = fmt::format("{}", cluster);
+  REQUIRE(formatted == "[not available]");
+
+  auto mutCluster = MutableExampleCluster{};
+  formatted = fmt::format("{}", mutCluster);
+  REQUIRE_FALSE(formatted.empty());
+  REQUIRE(formatted != "[not available]");
+
+  auto typeWithComponent = ExampleWithArrayComponent{};
+  formatted = fmt::format("{}", typeWithComponent);
+  REQUIRE_FALSE(formatted.empty());
+
+  auto nspComp = ex2::NamespaceInNamespaceStruct{};
+  formatted = fmt::format("{}", nspComp);
+  REQUIRE_FALSE(formatted.empty());
+}
+
 TEST_CASE("Cyclic dependencies", "[LEAK-FAIL][basics][relations][memory-management]") {
   SECTION("with collections") {
     auto coll1 = ExampleForCyclicDependency1Collection();
@@ -418,6 +457,9 @@ TEST_CASE("UserDataCollection basics", "[basics]") {
     coll.print(sstr);
 
     REQUIRE(sstr.str() == "[1, 2, 3]");
+
+    auto formatted = fmt::format("{}", coll);
+    REQUIRE_FALSE(formatted.empty());
   }
 
   SECTION("access") {
@@ -647,6 +689,19 @@ TEST_CASE("Equality", "[basics]") {
   REQUIRE(clu != cluster);
 }
 
+TEST_CASE("Collection formatting", "[basics]") {
+  ExampleClusterCollection clusters;
+  auto cluster = clusters.create();
+  cluster.energy(42.5f);
+  auto formatted = fmt::format("{}", clusters);
+  REQUIRE_FALSE(formatted.empty());
+
+  ExampleWithComponentCollection components;
+  auto comp = components.create();
+  formatted = fmt::format("{}", components);
+  REQUIRE_FALSE(formatted.empty());
+}
+
 TEST_CASE("UserInitialization", "[basics][code-gen]") {
   ExampleWithUserInitCollection coll;
   // Default initialization values should work even through the create factory