diff --git a/CHANGELOG.md b/CHANGELOG.md
index d618bea..7cf80f6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ### Added
  - Added ZIP features for examining the contents of an archive
  - Added FileNameEqualityComparer
+ - Added BiDictionary for one-to-one maps
 
 ## [3.5.1] - 2018-06-04
 ### Changed
diff --git a/ICD.Common.Utils/Collections/BiDictionary.cs b/ICD.Common.Utils/Collections/BiDictionary.cs
new file mode 100644
index 0000000..b9770b6
--- /dev/null
+++ b/ICD.Common.Utils/Collections/BiDictionary.cs
@@ -0,0 +1,184 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+
+namespace ICD.Common.Utils.Collections
+{
+	/// <summary>
+	/// Provides a 1-to-1 map of keys to values with O(1) Value->Key lookup time.
+	/// </summary>
+	/// <typeparam name="TKey"></typeparam>
+	/// <typeparam name="TValue"></typeparam>
+	public sealed class BiDictionary<TKey, TValue> : IDictionary<TKey, TValue>
+	{
+		private readonly Dictionary<TKey, TValue> m_KeyToValue;
+		private readonly Dictionary<TValue, TKey> m_ValueToKey;
+
+		#region Properties
+
+		public int Count { get { return m_KeyToValue.Count; } }
+
+		public bool IsReadOnly { get { return false; } }
+
+		public ICollection<TKey> Keys { get { return m_KeyToValue.Keys; } }
+
+		public ICollection<TValue> Values { get { return m_ValueToKey.Keys; } }
+
+		#endregion
+
+		/// <summary>
+		/// Constructor.
+		/// </summary>
+		public BiDictionary()
+		{
+			m_KeyToValue = new Dictionary<TKey, TValue>();
+			m_ValueToKey = new Dictionary<TValue, TKey>();
+		}
+
+		#region Methods
+
+		public void Clear()
+		{
+			m_KeyToValue.Clear();
+			m_ValueToKey.Clear();
+		}
+
+		public bool ContainsKey(TKey key)
+		{
+			return m_KeyToValue.ContainsKey(key);
+		}
+
+		public bool ContainsValue(TValue value)
+		{
+			return m_ValueToKey.ContainsKey(value);
+		}
+
+		public void Add(TKey key, TValue value)
+		{
+// ReSharper disable once CompareNonConstrainedGenericWithNull
+			if (key == null)
+				throw new ArgumentNullException("key");
+
+// ReSharper disable once CompareNonConstrainedGenericWithNull
+			if (value == null)
+				throw new ArgumentNullException("value");
+
+			if (m_KeyToValue.ContainsKey(key))
+				throw new ArgumentException("Key is already present in the dictionary", "key");
+
+			if (m_ValueToKey.ContainsKey(value))
+				throw new ArgumentException("Value is already present in the collection", "value");
+
+			m_KeyToValue.Add(key, value);
+			m_ValueToKey.Add(value, key);
+		}
+
+		public void Set(TKey key, TValue value)
+		{
+// ReSharper disable once CompareNonConstrainedGenericWithNull
+			if (key == null)
+				throw new ArgumentNullException("key");
+
+// ReSharper disable once CompareNonConstrainedGenericWithNull
+			if (value == null)
+				throw new ArgumentNullException("value");
+
+			m_KeyToValue[key] = value;
+			m_ValueToKey[value] = key;
+		}
+
+		public TKey GetKey(TValue value)
+		{
+			return m_ValueToKey[value];
+		}
+
+		public TValue GetValue(TKey key)
+		{
+			return m_KeyToValue[key];
+		}
+
+		public bool RemoveKey(TKey key)
+		{
+			if (!ContainsKey(key))
+				return false;
+
+			TValue value = m_KeyToValue[key];
+
+			m_KeyToValue.Remove(key);
+			m_ValueToKey.Remove(value);
+
+			return true;
+		}
+
+		public bool RemoveValue(TValue value)
+		{
+			if (!ContainsValue(value))
+				return false;
+
+			TKey key = m_ValueToKey[value];
+
+			return RemoveKey(key);
+		}
+
+		public bool TryGetValue(TKey key, out TValue value)
+		{
+			return m_KeyToValue.TryGetValue(key, out value);
+		}
+
+		public bool TryGetKey(TValue value, out TKey key)
+		{
+			return m_ValueToKey.TryGetValue(value, out key);
+		}
+
+		#endregion
+
+		#region IDictionary
+
+		TValue IDictionary<TKey, TValue>.this[TKey key] { get { return GetValue(key); } set { Set(key, value); } }
+
+		bool IDictionary<TKey, TValue>.Remove(TKey key)
+		{
+			return RemoveKey(key);
+		}
+
+		#endregion
+
+		#region ICollection
+
+		void ICollection<KeyValuePair<TKey, TValue>>.Add(KeyValuePair<TKey, TValue> item)
+		{
+			Add(item.Key, item.Value);
+		}
+
+		bool ICollection<KeyValuePair<TKey, TValue>>.Contains(KeyValuePair<TKey, TValue> item)
+		{
+			return (m_KeyToValue as IDictionary<TKey, TValue>).Contains(item);
+		}
+
+		bool ICollection<KeyValuePair<TKey, TValue>>.Remove(KeyValuePair<TKey, TValue> item)
+		{
+			return RemoveKey(item.Key);
+		}
+
+		void ICollection<KeyValuePair<TKey, TValue>>.CopyTo(KeyValuePair<TKey, TValue>[] array, int arrayIndex)
+		{
+			(m_KeyToValue as IDictionary<TKey, TValue>).CopyTo(array, arrayIndex);
+		}
+
+		#endregion
+
+		#region IEnumerable
+
+		public IEnumerator<KeyValuePair<TKey, TValue>> GetEnumerator()
+		{
+			return m_KeyToValue.GetEnumerator();
+		}
+
+		IEnumerator IEnumerable.GetEnumerator()
+		{
+			return GetEnumerator();
+		}
+
+		#endregion
+	}
+}
diff --git a/ICD.Common.Utils/ICD.Common.Utils_SimplSharp.csproj b/ICD.Common.Utils/ICD.Common.Utils_SimplSharp.csproj
index 9d0bd60..ed696f1 100644
--- a/ICD.Common.Utils/ICD.Common.Utils_SimplSharp.csproj
+++ b/ICD.Common.Utils/ICD.Common.Utils_SimplSharp.csproj
@@ -74,6 +74,7 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="Attributes\AbstractIcdAttribute.cs" />
+    <Compile Include="Collections\BiDictionary.cs" />
     <Compile Include="Collections\IcdOrderedDictionary.cs" />
     <Compile Include="Collections\PriorityQueue.cs" />
     <Compile Include="Collections\WeakKeyDictionary.cs" />