diff --git a/pkgs/development/libraries/isl/0.11.1.nix b/pkgs/development/libraries/isl/0.11.1.nix
deleted file mode 100644
index a11d9eca6a6e..000000000000
--- a/pkgs/development/libraries/isl/0.11.1.nix
+++ /dev/null
@@ -1,8 +0,0 @@
-import ./generic.nix {
-  version = "0.11.1";
-  urls = [
-    "https://src.fedoraproject.org/repo/pkgs/gcc/isl-0.11.1.tar.bz2/bce1586384d8635a76d2f017fb067cd2/isl-0.11.1.tar.bz2"
-  ];
-  sha256 = "13d9cqa5rzhbjq0xf0b2dyxag7pqa72xj9dhsa03m8ccr1a4npq9";
-  patches = [ ./fix-gcc-build.diff ];
-}
diff --git a/pkgs/development/libraries/isl/0.14.1.nix b/pkgs/development/libraries/isl/0.14.1.nix
deleted file mode 100644
index 1a368d2523e0..000000000000
--- a/pkgs/development/libraries/isl/0.14.1.nix
+++ /dev/null
@@ -1,8 +0,0 @@
-import ./generic.nix rec {
-  version = "0.14.1";
-  urls = [
-    "mirror://sourceforge/libisl/isl-${version}.tar.xz"
-    "https://libisl.sourceforge.io/isl-${version}.tar.xz"
-  ];
-  sha256 = "0xa6xagah5rywkywn19rzvbvhfvkmylhcxr6z9z7bz29cpiwk0l8";
-}
diff --git a/pkgs/development/libraries/isl/fix-gcc-build.diff b/pkgs/development/libraries/isl/fix-gcc-build.diff
deleted file mode 100644
index 6fbd1f9d478b..000000000000
--- a/pkgs/development/libraries/isl/fix-gcc-build.diff
+++ /dev/null
@@ -1,12 +0,0 @@
-diff -ru isl-0.11.1/include/isl/int.h isl-0.11.1.new/include/isl/int.h
---- isl-0.11.1/include/isl/int.h        2012-11-29 09:47:32.000000000 +0100
-+++ isl-0.11.1.new/include/isl/int.h    2013-10-27 15:35:31.348553812 +0100
-@@ -14,7 +14,7 @@
- #include <string.h>
- #include <gmp.h>
- #if defined(__cplusplus)
--#include <iostream>
-+#include <ostream>
- #endif
- 
- #if defined(__cplusplus)
diff --git a/pkgs/top-level/aliases.nix b/pkgs/top-level/aliases.nix
index 516b4ab6794e..8d13703498d2 100644
--- a/pkgs/top-level/aliases.nix
+++ b/pkgs/top-level/aliases.nix
@@ -709,6 +709,8 @@ mapAliases ({
   ipfs-migrator = kubo-migrator; # Added 2022-09-27
   iproute = iproute2; # moved from top-level 2021-03-14
   irrlichtmt = throw "irrlichtmt has been removed because it was moved into the Minetest repo"; # Added 2024-08-12
+  isl_0_11 = throw "isl_0_11 has been removed from Nixpkgs, as it is unmaintained and obsolete"; # Added 2024-09-13
+  isl_0_14 = throw "isl_0_14 has been removed from Nixpkgs, as it is unmaintained and obsolete"; # Added 2024-09-13
   iso-flags-png-320x420 = lib.warn "iso-flags-png-320x420 has been renamed to iso-flags-png-320x240" iso-flags-png-320x240; # Added 2024-07-17
 
   ### J ###
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 853bbcf60669..b0c2649aa50a 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -8941,8 +8941,6 @@ with pkgs;
   ised = callPackage ../tools/misc/ised { };
 
   isl = isl_0_20;
-  isl_0_11 = callPackage ../development/libraries/isl/0.11.1.nix { };
-  isl_0_14 = callPackage ../development/libraries/isl/0.14.1.nix { };
   isl_0_17 = callPackage ../development/libraries/isl/0.17.1.nix { };
   isl_0_20 = callPackage ../development/libraries/isl/0.20.0.nix { };
   isl_0_24 = callPackage ../development/libraries/isl/0.24.0.nix { };