diff --git a/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems b/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems
index 03a383506f0460..b155cf927dd7c3 100644
--- a/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems
+++ b/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems
@@ -484,7 +484,6 @@
     <Compile Include="$(MSBuildThisFileDirectory)System\SearchValues\Strings\StringSearchValuesAhoCorasick.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\SearchValues\Strings\StringSearchValuesRabinKarp.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\IndexOutOfRangeException.cs" />
-    <Compile Include="$(MSBuildThisFileDirectory)System\InlineArrays.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\InsufficientExecutionStackException.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\InsufficientMemoryException.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Int16.cs" />
diff --git a/src/libraries/System.Private.CoreLib/src/System/Diagnostics/Tracing/EventProvider.cs b/src/libraries/System.Private.CoreLib/src/System/Diagnostics/Tracing/EventProvider.cs
index c74d845a345def..a11dc0bfdd98bc 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Diagnostics/Tracing/EventProvider.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Diagnostics/Tracing/EventProvider.cs
@@ -6,6 +6,7 @@
 using System.Diagnostics;
 using System.Globalization;
 using System.Numerics;
+using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 using System.Threading;
 
@@ -478,8 +479,8 @@ internal unsafe bool WriteEvent(ref EventDescriptor eventDescriptor, IntPtr even
                 int index;
                 int refObjIndex = 0;
 
-                Debug.Assert(EtwAPIMaxRefObjCount == 8, $"{nameof(EtwAPIMaxRefObjCount)} must equal the number of fields in {nameof(EightObjects)}");
-                EightObjects eightObjectStack = default;
+                Debug.Assert(EtwAPIMaxRefObjCount == 8, $"{nameof(EtwAPIMaxRefObjCount)} must equal the number of fields in {nameof(InlineArray8<>)}");
+                InlineArray8<object?> eightObjectStack = default;
                 Span<int> refObjPosition = stackalloc int[EtwAPIMaxRefObjCount];
                 Span<object?> dataRefObj = eightObjectStack;
 
diff --git a/src/libraries/System.Private.CoreLib/src/System/IO/StreamWriter.cs b/src/libraries/System.Private.CoreLib/src/System/IO/StreamWriter.cs
index 4f370df7937b0f..83d65496368fe8 100644
--- a/src/libraries/System.Private.CoreLib/src/System/IO/StreamWriter.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/IO/StreamWriter.cs
@@ -531,8 +531,7 @@ public override void Write([StringSyntax(StringSyntaxAttribute.CompositeFormat)]
         {
             if (GetType() == typeof(StreamWriter))
             {
-                TwoObjects two = new TwoObjects(arg0, arg1);
-                WriteFormatHelper(format, two, appendNewLine: false);
+                WriteFormatHelper(format, [arg0, arg1], appendNewLine: false);
             }
             else
             {
@@ -544,8 +543,7 @@ public override void Write([StringSyntax(StringSyntaxAttribute.CompositeFormat)]
         {
             if (GetType() == typeof(StreamWriter))
             {
-                ThreeObjects three = new ThreeObjects(arg0, arg1, arg2);
-                WriteFormatHelper(format, three, appendNewLine: false);
+                WriteFormatHelper(format, [arg0, arg1, arg2], appendNewLine: false);
             }
             else
             {
@@ -602,8 +600,7 @@ public override void WriteLine([StringSyntax(StringSyntaxAttribute.CompositeForm
         {
             if (GetType() == typeof(StreamWriter))
             {
-                TwoObjects two = new TwoObjects(arg0, arg1);
-                WriteFormatHelper(format, two, appendNewLine: true);
+                WriteFormatHelper(format, [arg0, arg1], appendNewLine: true);
             }
             else
             {
@@ -615,8 +612,7 @@ public override void WriteLine([StringSyntax(StringSyntaxAttribute.CompositeForm
         {
             if (GetType() == typeof(StreamWriter))
             {
-                ThreeObjects three = new ThreeObjects(arg0, arg1, arg2);
-                WriteFormatHelper(format, three, appendNewLine: true);
+                WriteFormatHelper(format, [arg0, arg1, arg2], appendNewLine: true);
             }
             else
             {
diff --git a/src/libraries/System.Private.CoreLib/src/System/InlineArrays.cs b/src/libraries/System.Private.CoreLib/src/System/InlineArrays.cs
deleted file mode 100644
index 78394062ec942e..00000000000000
--- a/src/libraries/System.Private.CoreLib/src/System/InlineArrays.cs
+++ /dev/null
@@ -1,38 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-using System.Runtime.CompilerServices;
-
-namespace System
-{
-    [InlineArray(2)]
-    internal struct TwoObjects
-    {
-        private object? _arg0;
-
-        public TwoObjects(object? arg0, object? arg1)
-        {
-            this[0] = arg0;
-            this[1] = arg1;
-        }
-    }
-
-    [InlineArray(3)]
-    internal struct ThreeObjects
-    {
-        private object? _arg0;
-
-        public ThreeObjects(object? arg0, object? arg1, object? arg2)
-        {
-            this[0] = arg0;
-            this[1] = arg1;
-            this[2] = arg2;
-        }
-    }
-
-    [InlineArray(8)]
-    internal struct EightObjects
-    {
-        private object? _ref0;
-    }
-}
diff --git a/src/libraries/System.Private.CoreLib/src/System/SearchValues/Strings/AsciiStringSearchValuesTeddyBase.cs b/src/libraries/System.Private.CoreLib/src/System/SearchValues/Strings/AsciiStringSearchValuesTeddyBase.cs
index b764e3a22d81ee..0869ad1553f895 100644
--- a/src/libraries/System.Private.CoreLib/src/System/SearchValues/Strings/AsciiStringSearchValuesTeddyBase.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/SearchValues/Strings/AsciiStringSearchValuesTeddyBase.cs
@@ -109,7 +109,7 @@ internal abstract class AsciiStringSearchValuesTeddyBase<TBucketized, TStartCase
         // We may have up to 8 buckets.
         // If we have <= 8 strings, the buckets will be the strings themselves, and TBucketized.Value will be false.
         // If we have more than 8, the buckets will be string[], and TBucketized.Value will be true.
-        private readonly EightObjects _buckets;
+        private readonly InlineArray8<object?> _buckets;
 
         private readonly Vector512<byte>
             _n0Low, _n0High,
diff --git a/src/libraries/System.Private.CoreLib/src/System/String.Manipulation.cs b/src/libraries/System.Private.CoreLib/src/System/String.Manipulation.cs
index 7acc23d53c6535..07a25d1c6a5cce 100644
--- a/src/libraries/System.Private.CoreLib/src/System/String.Manipulation.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/String.Manipulation.cs
@@ -459,14 +459,12 @@ public static string Format([StringSyntax(StringSyntaxAttribute.CompositeFormat)
 
         public static string Format([StringSyntax(StringSyntaxAttribute.CompositeFormat)] string format, object? arg0, object? arg1)
         {
-            TwoObjects two = new TwoObjects(arg0, arg1);
-            return FormatHelper(null, format, two);
+            return FormatHelper(null, format, [arg0, arg1]);
         }
 
         public static string Format([StringSyntax(StringSyntaxAttribute.CompositeFormat)] string format, object? arg0, object? arg1, object? arg2)
         {
-            ThreeObjects three = new ThreeObjects(arg0, arg1, arg2);
-            return FormatHelper(null, format, three);
+            return FormatHelper(null, format, [arg0, arg1, arg2]);
         }
 
         public static string Format([StringSyntax(StringSyntaxAttribute.CompositeFormat)] string format, params object?[] args)
@@ -499,14 +497,12 @@ public static string Format(IFormatProvider? provider, [StringSyntax(StringSynta
 
         public static string Format(IFormatProvider? provider, [StringSyntax(StringSyntaxAttribute.CompositeFormat)] string format, object? arg0, object? arg1)
         {
-            TwoObjects two = new TwoObjects(arg0, arg1);
-            return FormatHelper(provider, format, two);
+            return FormatHelper(provider, format, [arg0, arg1]);
         }
 
         public static string Format(IFormatProvider? provider, [StringSyntax(StringSyntaxAttribute.CompositeFormat)] string format, object? arg0, object? arg1, object? arg2)
         {
-            ThreeObjects three = new ThreeObjects(arg0, arg1, arg2);
-            return FormatHelper(provider, format, three);
+            return FormatHelper(provider, format, [arg0, arg1, arg2]);
         }
 
         public static string Format(IFormatProvider? provider, [StringSyntax(StringSyntaxAttribute.CompositeFormat)] string format, params object?[] args)
diff --git a/src/libraries/System.Private.CoreLib/src/System/Text/StringBuilder.cs b/src/libraries/System.Private.CoreLib/src/System/Text/StringBuilder.cs
index 0dcc60a825f986..83f9306b16ee71 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Text/StringBuilder.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Text/StringBuilder.cs
@@ -1470,14 +1470,12 @@ public StringBuilder AppendFormat([StringSyntax(StringSyntaxAttribute.CompositeF
 
         public StringBuilder AppendFormat([StringSyntax(StringSyntaxAttribute.CompositeFormat)] string format, object? arg0, object? arg1)
         {
-            TwoObjects two = new TwoObjects(arg0, arg1);
-            return AppendFormat(null, format, (ReadOnlySpan<object?>)two);
+            return AppendFormat(null, format, [arg0, arg1]);
         }
 
         public StringBuilder AppendFormat([StringSyntax(StringSyntaxAttribute.CompositeFormat)] string format, object? arg0, object? arg1, object? arg2)
         {
-            ThreeObjects three = new ThreeObjects(arg0, arg1, arg2);
-            return AppendFormat(null, format, (ReadOnlySpan<object?>)three);
+            return AppendFormat(null, format, [arg0, arg1, arg2]);
         }
 
         public StringBuilder AppendFormat([StringSyntax(StringSyntaxAttribute.CompositeFormat)] string format, params object?[] args)
@@ -1518,14 +1516,12 @@ public StringBuilder AppendFormat(IFormatProvider? provider, [StringSyntax(Strin
 
         public StringBuilder AppendFormat(IFormatProvider? provider, [StringSyntax(StringSyntaxAttribute.CompositeFormat)] string format, object? arg0, object? arg1)
         {
-            TwoObjects two = new TwoObjects(arg0, arg1);
-            return AppendFormat(provider, format, (ReadOnlySpan<object?>)two);
+            return AppendFormat(provider, format, [arg0, arg1]);
         }
 
         public StringBuilder AppendFormat(IFormatProvider? provider, [StringSyntax(StringSyntaxAttribute.CompositeFormat)] string format, object? arg0, object? arg1, object? arg2)
         {
-            ThreeObjects three = new ThreeObjects(arg0, arg1, arg2);
-            return AppendFormat(provider, format, (ReadOnlySpan<object?>)three);
+            return AppendFormat(provider, format, [arg0, arg1, arg2]);
         }
 
         public StringBuilder AppendFormat(IFormatProvider? provider, [StringSyntax(StringSyntaxAttribute.CompositeFormat)] string format, params object?[] args)