diff --git a/src/KIM/kim_init.h b/src/KIM/kim_init.h
index 3311d4e13d..8fa3247b22 100644
--- a/src/KIM/kim_init.h
+++ b/src/KIM/kim_init.h
@@ -66,7 +66,6 @@ CommandStyle(kim_init,KimInit)
 #define LMP_KIM_INIT_H
 
 #include "pointers.h"
-#include <string>
 
 // Forward declaration.
 typedef struct KIM_Model KIM_Model;
diff --git a/src/KIM/kim_interactions.h b/src/KIM/kim_interactions.h
index 414c7b39d5..071e5b284f 100644
--- a/src/KIM/kim_interactions.h
+++ b/src/KIM/kim_interactions.h
@@ -66,7 +66,6 @@ CommandStyle(kim_interactions,KimInteractions)
 #define LMP_KIM_INTERACTIONS_H
 
 #include "pointers.h"
-#include <string>
 
 namespace LAMMPS_NS {
 
diff --git a/src/KIM/kim_param.h b/src/KIM/kim_param.h
index a4e26451f2..e4fc5ce59a 100644
--- a/src/KIM/kim_param.h
+++ b/src/KIM/kim_param.h
@@ -65,7 +65,6 @@ CommandStyle(kim_param, KimParam)
 #define LMP_KIM_PARAM_H
 
 #include "pointers.h"
-#include <string>
 
 namespace LAMMPS_NS
 {
diff --git a/src/KIM/kim_query.h b/src/KIM/kim_query.h
index 6888f911f4..e1c49ed71d 100644
--- a/src/KIM/kim_query.h
+++ b/src/KIM/kim_query.h
@@ -64,7 +64,6 @@ CommandStyle(kim_query,KimQuery)
 #define LMP_KIM_QUERY_H
 
 #include "pointers.h"
-#include <string>
 
 namespace LAMMPS_NS {
 
diff --git a/src/KOKKOS/min_linesearch_kokkos.cpp b/src/KOKKOS/min_linesearch_kokkos.cpp
index 3c94f07233..4306a5bd3b 100644
--- a/src/KOKKOS/min_linesearch_kokkos.cpp
+++ b/src/KOKKOS/min_linesearch_kokkos.cpp
@@ -18,13 +18,12 @@
 #include "min_linesearch_kokkos.h"
 
 #include "atom_kokkos.h"
-#include "modify.h"
-#include "fix_minimize_kokkos.h"
-#include "pair.h"
-#include "output.h"
-#include "thermo.h"
-#include "error.h"
 #include "atom_masks.h"
+#include "error.h"
+#include "fix_minimize_kokkos.h"
+#include "output.h"
+#include "pair.h"
+#include "thermo.h"
 
 #include <cmath>
 
diff --git a/src/KSPACE/pppm_dipole.cpp b/src/KSPACE/pppm_dipole.cpp
index 1a87c81bee..1b7d325326 100644
--- a/src/KSPACE/pppm_dipole.cpp
+++ b/src/KSPACE/pppm_dipole.cpp
@@ -16,26 +16,23 @@
 ------------------------------------------------------------------------- */
 
 #include "pppm_dipole.h"
-#include <mpi.h>
-#include <cstring>
-#include <string>
-#include <cmath>
+
 #include "atom.h"
 #include "comm.h"
-#include "gridcomm.h"
-#include "force.h"
-#include "pair.h"
 #include "domain.h"
-#include "fft3d_wrap.h"
-#include "remap_wrap.h"
-#include "memory.h"
 #include "error.h"
-#include "update.h"
-#include "utils.h"
-#include "fmt/format.h"
-
+#include "fft3d_wrap.h"
+#include "force.h"
+#include "gridcomm.h"
 #include "math_const.h"
 #include "math_special.h"
+#include "memory.h"
+#include "pair.h"
+#include "remap_wrap.h"
+#include "update.h"
+
+#include <cmath>
+#include <cstring>
 
 using namespace LAMMPS_NS;
 using namespace MathConst;
diff --git a/src/MANYBODY/pair_polymorphic.cpp b/src/MANYBODY/pair_polymorphic.cpp
index 4c8ebaf8ad..0f7fd7a1c7 100644
--- a/src/MANYBODY/pair_polymorphic.cpp
+++ b/src/MANYBODY/pair_polymorphic.cpp
@@ -18,20 +18,19 @@
 
 #include "pair_polymorphic.h"
 
-#include <cmath>
-
-#include <cstring>
 #include "atom.h"
-#include "neighbor.h"
+#include "comm.h"
+#include "error.h"
+#include "force.h"
+#include "memory.h"
 #include "neigh_list.h"
 #include "neigh_request.h"
-#include "force.h"
-#include "comm.h"
-#include "memory.h"
-#include "error.h"
-
-#include "tokenizer.h"
+#include "neighbor.h"
 #include "potential_file_reader.h"
+#include "tokenizer.h"
+
+#include <cmath>
+#include <cstring>
 
 using namespace LAMMPS_NS;
 
diff --git a/src/MANYBODY/pair_polymorphic.h b/src/MANYBODY/pair_polymorphic.h
index 18956699d7..2593905b22 100644
--- a/src/MANYBODY/pair_polymorphic.h
+++ b/src/MANYBODY/pair_polymorphic.h
@@ -22,7 +22,6 @@ PairStyle(polymorphic,PairPolymorphic)
 
 #include "pair.h"
 #include <cmath>
-#include <cstring>
 
 namespace LAMMPS_NS {
 
diff --git a/src/MC/fix_widom.cpp b/src/MC/fix_widom.cpp
index d7fdf69b86..94b2481742 100644
--- a/src/MC/fix_widom.cpp
+++ b/src/MC/fix_widom.cpp
@@ -20,7 +20,6 @@
 #include "angle.h"
 #include "atom.h"
 #include "atom_vec.h"
-#include "atom_vec_hybrid.h"
 #include "bond.h"
 #include "comm.h"
 #include "compute.h"
diff --git a/src/MC/fix_widom.h b/src/MC/fix_widom.h
index 05060e76ac..19102e4f4a 100644
--- a/src/MC/fix_widom.h
+++ b/src/MC/fix_widom.h
@@ -20,7 +20,6 @@ FixStyle(widom,FixWidom)
 #ifndef LMP_FIX_WIDOM_H
 #define LMP_FIX_WIDOM_H
 
-#include <cstdio>
 #include "fix.h"
 
 namespace LAMMPS_NS {
diff --git a/src/MLIAP/mliap_data.cpp b/src/MLIAP/mliap_data.cpp
index 28f9a988d8..a7e50012cb 100644
--- a/src/MLIAP/mliap_data.cpp
+++ b/src/MLIAP/mliap_data.cpp
@@ -19,8 +19,6 @@
 #include "mliap_model.h"
 #include "neigh_list.h"
 
-#include <cstring>
-
 using namespace LAMMPS_NS;
 
 MLIAPData::MLIAPData(LAMMPS *lmp, int gradgradflag_in, int *map_in,
diff --git a/src/USER-MISC/fix_accelerate_cos.cpp b/src/USER-MISC/fix_accelerate_cos.cpp
index 4e84b47ac3..4c15685556 100644
--- a/src/USER-MISC/fix_accelerate_cos.cpp
+++ b/src/USER-MISC/fix_accelerate_cos.cpp
@@ -23,6 +23,8 @@
 #include "force.h"
 #include "math_const.h"
 
+#include <cmath>
+
 using namespace LAMMPS_NS;
 using namespace FixConst;
 
diff --git a/src/USER-MISC/fix_propel_self.cpp b/src/USER-MISC/fix_propel_self.cpp
index e17ef4652f..522c2eb4a5 100644
--- a/src/USER-MISC/fix_propel_self.cpp
+++ b/src/USER-MISC/fix_propel_self.cpp
@@ -27,6 +27,7 @@
 #include "math_extra.h"
 
 #include <cctype>
+#include <cmath>
 #include <cstring>
 
 using namespace LAMMPS_NS;
diff --git a/src/USER-MISC/fix_wall_reflect_stochastic.h b/src/USER-MISC/fix_wall_reflect_stochastic.h
index 0568dc8ae5..558ad7d084 100644
--- a/src/USER-MISC/fix_wall_reflect_stochastic.h
+++ b/src/USER-MISC/fix_wall_reflect_stochastic.h
@@ -20,7 +20,6 @@ FixStyle(wall/reflect/stochastic,FixWallReflectStochastic)
 #ifndef LMP_FIX_WALL_REFLECT_STOCHASTIC_H
 #define LMP_FIX_WALL_REFLECT_STOCHASTIC_H
 
-#include "random_mars.h"
 #include "fix_wall_reflect.h"
 
 namespace LAMMPS_NS {
diff --git a/src/USER-MISC/pair_local_density.cpp b/src/USER-MISC/pair_local_density.cpp
index f8b813ef0b..404f6e2db1 100644
--- a/src/USER-MISC/pair_local_density.cpp
+++ b/src/USER-MISC/pair_local_density.cpp
@@ -28,7 +28,6 @@
 #include "neigh_list.h"
 #include "neighbor.h"
 
-#include <cmath>
 #include <cstring>
 
 using namespace LAMMPS_NS;
diff --git a/src/potential_file_reader.h b/src/potential_file_reader.h
index 57aa827638..d3befca282 100644
--- a/src/potential_file_reader.h
+++ b/src/potential_file_reader.h
@@ -18,7 +18,7 @@
 #ifndef LMP_POTENTIAL_FILE_READER_H
 #define LMP_POTENTIAL_FILE_READER_H
 
-#include "pointers.h"
+#include "pointers.h"           // IWYU pragma: export
 #include "tokenizer.h"
 
 namespace LAMMPS_NS
diff --git a/src/text_file_reader.h b/src/text_file_reader.h
index e74a285961..65af0a08d9 100644
--- a/src/text_file_reader.h
+++ b/src/text_file_reader.h
@@ -18,11 +18,10 @@
 #ifndef LMP_TEXT_FILE_READER_H
 #define LMP_TEXT_FILE_READER_H
 
-#include <cstdio>
-#include <exception>
-
 #include "tokenizer.h"
 
+#include <cstdio>
+
 namespace LAMMPS_NS
 {
   class TextFileReader {
diff --git a/src/tokenizer.cpp b/src/tokenizer.cpp
index 33a81db748..3b172181a2 100644
--- a/src/tokenizer.cpp
+++ b/src/tokenizer.cpp
@@ -17,11 +17,11 @@
 
 #include "tokenizer.h"
 #include "utils.h"
+#include "fmt/format.h"
+
 #include <exception>
 #include <utility>
 
-#include "fmt/format.h"
-
 using namespace LAMMPS_NS;
 
 TokenizerException::TokenizerException(const std::string & msg, const std::string & token){