diff --git a/Source/Core/Common/StringUtil.h b/Source/Core/Common/StringUtil.h
@@ -44,8 +44,8 @@ inline void CharArrayFromFormat(char (&out)[Count], const char* format, ...)
 // Good
 std::string ArrayToString(const u8* data, u32 size, int line_len = 20, bool spaces = true);
 
-std::string StripSpaces(const std::string& s);
-std::string StripQuotes(const std::string& s);
+std::string_view StripSpaces(std::string_view s);
+std::string_view StripQuotes(std::string_view s);
 
 bool TryParse(const std::string& str, bool* output);
 bool TryParse(const std::string& str, u16* output);
@@ -107,50 +107,50 @@ std::string HexDump(const u8* data, size_t size);
 // TODO: kill this
 bool AsciiToHex(const std::string& _szValue, u32& result);
 
-std::string TabsToSpaces(int tab_size, const std::string& in);
+std::string TabsToSpaces(int tab_size, std::string str);
 
 std::vector<std::string> SplitString(const std::string& str, char delim);
 std::string JoinStrings(const std::vector<std::string>& strings, const std::string& delimiter);
 
 // "C:/Windows/winhelp.exe" to "C:/Windows/", "winhelp", ".exe"
-bool SplitPath(const std::string& full_path, std::string* _pPath, std::string* _pFilename,
-               std::string* _pExtension);
+bool SplitPath(std::string_view full_path, std::string* path, std::string* filename,
+               std::string* extension);
 
-void BuildCompleteFilename(std::string& _CompleteFilename, const std::string& _Path,
-                           const std::string& _Filename);
-std::string ReplaceAll(std::string result, const std::string& src, const std::string& dest);
+void BuildCompleteFilename(std::string& complete_filename, std::string_view path,
+                           std::string_view filename);
+std::string ReplaceAll(std::string result, std::string_view src, std::string_view dest);
 
-bool StringBeginsWith(const std::string& str, const std::string& begin);
-bool StringEndsWith(const std::string& str, const std::string& end);
+bool StringBeginsWith(std::string_view str, std::string_view begin);
+bool StringEndsWith(std::string_view str, std::string_view end);
 void StringPopBackIf(std::string* s, char c);
 
-std::string CP1252ToUTF8(const std::string& str);
-std::string SHIFTJISToUTF8(const std::string& str);
-std::string UTF8ToSHIFTJIS(const std::string& str);
-std::string UTF16ToUTF8(const std::wstring& str);
+std::string CP1252ToUTF8(std::string_view str);
+std::string SHIFTJISToUTF8(std::string_view str);
+std::string UTF8ToSHIFTJIS(std::string_view str);
+std::string UTF16ToUTF8(std::wstring_view str);
 std::string UTF16BEToUTF8(const char16_t* str, size_t max_size);  // Stops at \0
 
 #ifdef _WIN32
 
-std::wstring UTF8ToUTF16(const std::string& str);
+std::wstring UTF8ToUTF16(std::string_view str);
 
 #ifdef _UNICODE
-inline std::string TStrToUTF8(const std::wstring& str)
+inline std::string TStrToUTF8(std::wstring_view str)
 {
   return UTF16ToUTF8(str);
 }
 
-inline std::wstring UTF8ToTStr(const std::string& str)
+inline std::wstring UTF8ToTStr(std::string_view str)
 {
   return UTF8ToUTF16(str);
 }
 #else
-inline std::string TStrToUTF8(const std::string& str)
+inline std::string TStrToUTF8(std::string_view str)
 {
   return str;
 }
 
-inline std::string UTF8ToTStr(const std::string& str)
+inline std::string UTF8ToTStr(std::string_view str)
 {
   return str;
 }

diff --git a/Source/Core/Core/PowerPC/PPCSymbolDB.cpp b/Source/Core/Core/PowerPC/PPCSymbolDB.cpp
@@ -8,6 +8,7 @@
 #include <cstring>
 #include <map>
 #include <string>
+#include <string_view>
 #include <utility>
 #include <vector>
 
@@ -298,7 +299,7 @@ bool PPCSymbolDB::LoadMap(const std::string& filename, bool bad)
     // Detect two columns with three columns fallback
     if (column_count == 0)
     {
-      const std::string stripped_line = StripSpaces(line);
+      const std::string_view stripped_line = StripSpaces(line);
       if (std::count(stripped_line.begin(), stripped_line.end(), ' ') == 1)
         column_count = 2;
       else

diff --git a/Source/Core/Core/TitleDatabase.cpp b/Source/Core/Core/TitleDatabase.cpp
@@ -7,6 +7,8 @@
 #include <cstddef>
 #include <fstream>
 #include <functional>
+#include <string>
+#include <string_view>
 #include <unordered_map>
 #include <utility>
 
@@ -39,7 +41,7 @@ static Map LoadMap(const std::string& file_path)
     const size_t equals_index = line.find('=');
     if (equals_index != std::string::npos)
     {
-      const std::string game_id = StripSpaces(line.substr(0, equals_index));
+      const std::string_view game_id = StripSpaces(line.substr(0, equals_index));
       if (game_id.length() >= 4)
         map.emplace(game_id, StripSpaces(line.substr(equals_index + 1)));
     }

diff --git a/Source/Core/DolphinQt/Settings/USBDeviceAddToWhitelistDialog.cpp b/Source/Core/DolphinQt/Settings/USBDeviceAddToWhitelistDialog.cpp
@@ -4,6 +4,8 @@
 
 #include "DolphinQt/Settings/USBDeviceAddToWhitelistDialog.h"
 
+#include <string_view>
+
 #include <QButtonGroup>
 #include <QDialog>
 #include <QDialogButtonBox>
@@ -27,7 +29,7 @@
 
 #include "UICommon/USBUtils.h"
 
-static bool IsValidUSBIDString(const std::string& string)
+static bool IsValidUSBIDString(std::string_view string)
 {
   if (string.empty() || string.length() > 4)
     return false;
@@ -124,8 +126,8 @@ void USBDeviceAddToWhitelistDialog::RefreshDeviceList()
 
 void USBDeviceAddToWhitelistDialog::AddUSBDeviceToWhitelist()
 {
-  const std::string vid_string = StripSpaces(device_vid_textbox->text().toStdString());
-  const std::string pid_string = StripSpaces(device_pid_textbox->text().toStdString());
+  const std::string_view vid_string = StripSpaces(device_vid_textbox->text().toStdString());
+  const std::string_view pid_string = StripSpaces(device_pid_textbox->text().toStdString());
   if (!IsValidUSBIDString(vid_string))
   {
     // i18n: Here, VID means Vendor ID (for a USB device).
@@ -151,8 +153,8 @@ void USBDeviceAddToWhitelistDialog::AddUSBDeviceToWhitelist()
     return;
   }
 
-  const u16 vid = static_cast<u16>(std::stoul(vid_string, nullptr, 16));
-  const u16 pid = static_cast<u16>(std::stoul(pid_string, nullptr, 16));
+  const u16 vid = static_cast<u16>(std::stoul(std::string(vid_string), nullptr, 16));
+  const u16 pid = static_cast<u16>(std::stoul(std::string(pid_string), nullptr, 16));
 
   if (SConfig::GetInstance().IsUSBDeviceWhitelisted({vid, pid}))
   {

diff --git a/Source/Core/InputCommon/ControllerInterface/OSX/OSX.mm b/Source/Core/InputCommon/ControllerInterface/OSX/OSX.mm
@@ -141,7 +141,7 @@ static void DeviceDebugPrint(IOHIDDeviceRef device)
 {
   const NSString* name = reinterpret_cast<const NSString*>(
       IOHIDDeviceGetProperty(inIOHIDDeviceRef, CFSTR(kIOHIDProductKey)));
-  return (name != nullptr) ? StripSpaces([name UTF8String]) : "Unknown device";
+  return (name != nullptr) ? std::string(StripSpaces([name UTF8String])) : "Unknown device";
 }
 
 static void DeviceRemovalCallback(void* inContext, IOReturn inResult, void* inSender,

diff --git a/Source/Core/InputCommon/ControllerInterface/OSX/OSXJoystick.mm b/Source/Core/InputCommon/ControllerInterface/OSX/OSXJoystick.mm
@@ -164,7 +164,7 @@
 {
   std::ostringstream s;
   s << IOHIDElementGetUsage(m_element);
-  return std::string("Button ") + StripSpaces(s.str());
+  return std::string("Button ").append(StripSpaces(s.str()));
 }
 
 Joystick::Axis::Axis(IOHIDElementRef element, IOHIDDeviceRef device, direction dir)

diff --git a/Source/Core/InputCommon/ControllerInterface/evdev/evdev.cpp b/Source/Core/InputCommon/ControllerInterface/evdev/evdev.cpp
@@ -313,7 +313,7 @@ std::string evdevDevice::Button::GetName() const
   {
     const char* name = libevdev_event_code_get_name(EV_KEY, m_code);
     if (name)
-      return StripSpaces(name);
+      return std::string(StripSpaces(name));
   }
   // But controllers use codes above 0x100, and the standard label often doesn't match.
   // We are better off with Button 0 and so on.

diff --git a/Source/Core/InputCommon/InputProfile.cpp b/Source/Core/InputCommon/InputProfile.cpp
@@ -32,7 +32,7 @@ std::vector<std::string> GetProfilesFromSetting(const std::string& setting, cons
   std::vector<std::string> result;
   for (const std::string& setting_choice : setting_choices)
   {
-    const std::string path = root + StripSpaces(setting_choice);
+    const std::string path = root + std::string(StripSpaces(setting_choice));
     if (File::IsDirectory(path))
     {
       const auto files_under_directory = Common::DoFileSearch({path}, {".ini"}, true);

diff --git a/Source/Core/VideoCommon/PostProcessing.cpp b/Source/Core/VideoCommon/PostProcessing.cpp
@@ -6,6 +6,7 @@
 
 #include <sstream>
 #include <string>
+#include <string_view>
 
 #include "Common/Assert.h"
 #include "Common/CommonPaths.h"
@@ -117,16 +118,15 @@ void PostProcessingConfiguration::LoadOptions(const std::string& code)
   GLSLStringOption* current_strings = nullptr;
   while (!in.eof())
   {
-    std::string line;
-
-    if (std::getline(in, line))
+    std::string line_str;
+    if (std::getline(in, line_str))
     {
+      std::string_view line = line_str;
+
 #ifndef _WIN32
       // Check for CRLF eol and convert it to LF
       if (!line.empty() && line.at(line.size() - 1) == '\r')
-      {
-        line.erase(line.size() - 1);
-      }
+        line.remove_suffix(1);
 #endif
 
       if (!line.empty())
@@ -138,8 +138,8 @@ void PostProcessingConfiguration::LoadOptions(const std::string& code)
           if (endpos != std::string::npos)
           {
             // New section!
-            std::string sub = line.substr(1, endpos - 1);
-            option_strings.push_back({sub});
+            std::string_view sub = line.substr(1, endpos - 1);
+            option_strings.push_back({std::string(sub)});
             current_strings = &option_strings.back();
           }
         }