diff --git a/include/zephyr/posix/unistd.h b/include/zephyr/posix/unistd.h
index d5782200275..990211730ea 100644
--- a/include/zephyr/posix/unistd.h
+++ b/include/zephyr/posix/unistd.h
@@ -238,6 +238,7 @@ ssize_t write(int file, const void *buffer, size_t count);
 ssize_t read(int file, void *buffer, size_t count);
 off_t lseek(int file, off_t offset, int whence);
 int fsync(int fd);
+int ftruncate(int fd, off_t length);
 
 /* File System related operations */
 int rename(const char *old, const char *newp);
diff --git a/lib/posix/options/fs.c b/lib/posix/options/fs.c
index d7203d150e9..8285ef1648b 100644
--- a/lib/posix/options/fs.c
+++ b/lib/posix/options/fs.c
@@ -416,3 +416,18 @@ int mkdir(const char *path, mode_t mode)
 
 	return 0;
 }
+
+/**
+ * @brief Truncate file to specified length.
+ *
+ */
+int ftruncate(int fd, off_t length)
+{
+	struct posix_fs_desc *ptr = NULL;
+
+	ptr = z_get_fd_obj(fd, NULL, EBADF);
+	if (!ptr)
+		return -1;
+
+	return fs_truncate(&ptr->file, length);
+}