diff --git a/eng/native/configurecompiler.cmake b/eng/native/configurecompiler.cmake
index 474402706f40ff..e03f9380f3abcc 100644
--- a/eng/native/configurecompiler.cmake
+++ b/eng/native/configurecompiler.cmake
@@ -468,6 +468,14 @@ if (CLR_CMAKE_HOST_UNIX)
     endif()
   elseif(CLR_CMAKE_HOST_NETBSD)
     message("Detected NetBSD amd64")
+  elseif(CLR_CMAKE_HOST_OPENBSD)
+    if(CLR_CMAKE_HOST_UNIX_ARM64)
+      message("Detected OpenBSD aarch64")
+    elseif(CLR_CMAKE_HOST_UNIX_AMD64)
+      message("Detected OpenBSD amd64")
+    else()
+      message(FATAL_ERROR "Unsupported OpenBSD architecture")
+    endif()
   elseif(CLR_CMAKE_HOST_SUNOS)
     message("Detected SunOS amd64")
   elseif(CLR_CMAKE_HOST_HAIKU)
@@ -785,6 +793,8 @@ if(CLR_CMAKE_TARGET_UNIX)
     endif()
   elseif(CLR_CMAKE_TARGET_NETBSD)
     add_compile_definitions($<$<NOT:$<BOOL:$<TARGET_PROPERTY:IGNORE_DEFAULT_TARGET_OS>>>:TARGET_NETBSD>)
+  elseif(CLR_CMAKE_TARGET_OPENBSD)
+    add_compile_definitions($<$<NOT:$<BOOL:$<TARGET_PROPERTY:IGNORE_DEFAULT_TARGET_OS>>>:TARGET_OPENBSD>)
   elseif(CLR_CMAKE_TARGET_SUNOS)
     add_compile_definitions($<$<NOT:$<BOOL:$<TARGET_PROPERTY:IGNORE_DEFAULT_TARGET_OS>>>:TARGET_SUNOS>)
     if(CLR_CMAKE_TARGET_OS_ILLUMOS)
diff --git a/src/native/libs/System.Native/pal_io.c b/src/native/libs/System.Native/pal_io.c
index 7a7ea2b83c5dd2..92c39ef0522777 100644
--- a/src/native/libs/System.Native/pal_io.c
+++ b/src/native/libs/System.Native/pal_io.c
@@ -160,8 +160,10 @@ c_static_assert((int)PAL_DT_BLK == (int)DT_BLK);
 c_static_assert((int)PAL_DT_REG == (int)DT_REG);
 c_static_assert((int)PAL_DT_LNK == (int)DT_LNK);
 c_static_assert((int)PAL_DT_SOCK == (int)DT_SOCK);
+#ifdef DT_WHT // not available in OpenBSD
 c_static_assert((int)PAL_DT_WHT == (int)DT_WHT);
 #endif
+#endif
 
 // Validate that our Lock enum value are correct for the platform
 c_static_assert(PAL_LOCK_SH == LOCK_SH);
@@ -1534,7 +1536,9 @@ int32_t SystemNative_GetPeerID(intptr_t socket, uid_t* euid)
 
     // ucred causes Emscripten to fail even though it's defined,
     // but getting peer credentials won't work for WebAssembly anyway
-#if defined(SO_PEERCRED) && !defined(TARGET_WASM)
+    // ucred also causes OpeBSD to fail because the struct definition is named
+    // differently and on OpenBSD we can use getpeereid(3) instead anyways.
+#if defined(SO_PEERCRED) && !defined(TARGET_WASM) && !defined(TARGET_OPENBSD)
     struct ucred creds;
     socklen_t len = sizeof(creds);
     if (getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &creds, &len) == 0)
diff --git a/src/native/libs/configure.cmake b/src/native/libs/configure.cmake
index 4da74e115c6db8..e932f2f0ee1412 100644
--- a/src/native/libs/configure.cmake
+++ b/src/native/libs/configure.cmake
@@ -113,6 +113,7 @@ check_c_source_compiles(
 
 check_c_source_compiles(
     "
+    #include <sys/types.h>
     #include <sys/mount.h>
     int main(void)
     {
@@ -336,7 +337,7 @@ check_struct_has_member(
 check_struct_has_member(
     "struct statfs"
     f_fstypename
-    "sys/mount.h"
+    "sys/types.h;sys/mount.h"
     HAVE_STATFS_FSTYPENAME)
 
 check_struct_has_member(