diff --git a/Source/Core/DiscIO/DirectoryBlob.h b/Source/Core/DiscIO/DirectoryBlob.h
index d5b5c42545..c2cd2521d6 100644
--- a/Source/Core/DiscIO/DirectoryBlob.h
+++ b/Source/Core/DiscIO/DirectoryBlob.h
@@ -219,10 +219,10 @@ private:
                 std::vector<u8>* disc_header);
 
   // FST creation
-  void WriteEntryData(std::vector<u8>* fst_data, u32* entry_offset, u8 type, u32 name_offset,
-                      u64 data_offset, u64 length, u32 address_shift);
-  void WriteEntryName(std::vector<u8>* fst_data, u32* name_offset, const std::string& name,
-                      u64 name_table_offset);
+  static void WriteEntryData(std::vector<u8>* fst_data, u32* entry_offset, u8 type, u32 name_offset,
+                             u64 data_offset, u64 length, u32 address_shift);
+  static void WriteEntryName(std::vector<u8>* fst_data, u32* name_offset, const std::string& name,
+                             u64 name_table_offset);
   void WriteDirectory(std::vector<u8>* fst_data, std::vector<FSTBuilderNode>* parent_entries,
                       u32* fst_offset, u32* name_offset, u64* data_offset, u32 parent_entry_index,
                       u64 name_table_offset);
diff --git a/Source/Core/DiscIO/DiscScrubber.h b/Source/Core/DiscIO/DiscScrubber.h
index cf69615fdd..f671d36543 100644
--- a/Source/Core/DiscIO/DiscScrubber.h
+++ b/Source/Core/DiscIO/DiscScrubber.h
@@ -39,8 +39,10 @@ private:
   void MarkAsUsed(u64 offset, u64 size);
   void MarkAsUsedE(u64 partition_data_offset, u64 offset, u64 size);
   u64 ToClusterOffset(u64 offset) const;
-  bool ReadFromVolume(const Volume& disc, u64 offset, u32& buffer, const Partition& partition);
-  bool ReadFromVolume(const Volume& disc, u64 offset, u64& buffer, const Partition& partition);
+  static bool ReadFromVolume(const Volume& disc, u64 offset, u32& buffer,
+                             const Partition& partition);
+  static bool ReadFromVolume(const Volume& disc, u64 offset, u64& buffer,
+                             const Partition& partition);
   bool ParseDisc(const Volume& disc);
   bool ParsePartitionData(const Volume& disc, const Partition& partition);
   void ParseFileSystemData(u64 partition_data_offset, const FileInfo& directory);
diff --git a/Source/Core/DiscIO/FileSystemGCWii.cpp b/Source/Core/DiscIO/FileSystemGCWii.cpp
index 7680c47abb..e0f49c7f30 100644
--- a/Source/Core/DiscIO/FileSystemGCWii.cpp
+++ b/Source/Core/DiscIO/FileSystemGCWii.cpp
@@ -305,7 +305,7 @@ std::unique_ptr<FileInfo> FileSystemGCWii::FindFileInfo(std::string_view path) c
 }
 
 std::unique_ptr<FileInfo> FileSystemGCWii::FindFileInfo(std::string_view path,
-                                                        const FileInfo& file_info) const
+                                                        const FileInfo& file_info)
 {
   // Given a path like "directory1/directory2/fileA.bin", this function will
   // find directory1 and then call itself to search for "directory2/fileA.bin".
diff --git a/Source/Core/DiscIO/FileSystemGCWii.h b/Source/Core/DiscIO/FileSystemGCWii.h
index b25f2e295e..9c77713678 100644
--- a/Source/Core/DiscIO/FileSystemGCWii.h
+++ b/Source/Core/DiscIO/FileSystemGCWii.h
@@ -102,7 +102,7 @@ private:
   // Maps the end offset of files to FST indexes
   mutable std::map<u64, u32> m_offset_file_info_cache;
 
-  std::unique_ptr<FileInfo> FindFileInfo(std::string_view path, const FileInfo& file_info) const;
+  static std::unique_ptr<FileInfo> FindFileInfo(std::string_view path, const FileInfo& file_info);
 };
 
 }  // namespace DiscIO
diff --git a/Source/Core/DiscIO/NANDImporter.h b/Source/Core/DiscIO/NANDImporter.h
index cc2bc69381..831e6b9dd4 100644
--- a/Source/Core/DiscIO/NANDImporter.h
+++ b/Source/Core/DiscIO/NANDImporter.h
@@ -66,7 +66,7 @@ public:
 private:
   bool ReadNANDBin(const std::string& path_to_bin, std::function<std::string()> get_otp_dump_path);
   bool FindSuperblock();
-  std::string GetPath(const NANDFSTEntry& entry, const std::string& parent_path);
+  static std::string GetPath(const NANDFSTEntry& entry, const std::string& parent_path);
   std::string FormatDebugString(const NANDFSTEntry& entry);
   void ProcessEntry(u16 entry_number, const std::string& parent_path);
   std::vector<u8> GetEntryData(const NANDFSTEntry& entry);
@@ -84,7 +84,7 @@ private:
 template <>
 struct fmt::formatter<DiscIO::NANDImporter::NANDFSTEntry>
 {
-  constexpr auto parse(format_parse_context& ctx) { return ctx.begin(); }
+  static constexpr auto parse(format_parse_context& ctx) { return ctx.begin(); }
   template <typename FormatContext>
   auto format(const DiscIO::NANDImporter::NANDFSTEntry& entry, FormatContext& ctx) const
   {
diff --git a/Source/Core/DiscIO/VolumeDisc.cpp b/Source/Core/DiscIO/VolumeDisc.cpp
index b32ddc6d17..3255f65a8d 100644
--- a/Source/Core/DiscIO/VolumeDisc.cpp
+++ b/Source/Core/DiscIO/VolumeDisc.cpp
@@ -39,7 +39,7 @@ Country VolumeDisc::GetCountry(const Partition& partition) const
   return CountryCodeToCountry(country_byte, GetVolumeType(), region, revision);
 }
 
-Region VolumeDisc::RegionCodeToRegion(std::optional<u32> region_code) const
+Region VolumeDisc::RegionCodeToRegion(std::optional<u32> region_code)
 {
   if (!region_code)
     return Region::Unknown;
diff --git a/Source/Core/DiscIO/VolumeDisc.h b/Source/Core/DiscIO/VolumeDisc.h
index 17c76ae689..847bc98dbb 100644
--- a/Source/Core/DiscIO/VolumeDisc.h
+++ b/Source/Core/DiscIO/VolumeDisc.h
@@ -25,7 +25,7 @@ public:
   bool IsNKit() const override;
 
 protected:
-  Region RegionCodeToRegion(std::optional<u32> region_code) const;
+  static Region RegionCodeToRegion(std::optional<u32> region_code);
   void AddGamePartitionToSyncHash(Common::SHA1::Context* context) const;
 };