Index: lldb/source/Commands/CommandObjectProcess.cpp
===================================================================
--- lldb/source/Commands/CommandObjectProcess.cpp
+++ lldb/source/Commands/CommandObjectProcess.cpp
@@ -1034,6 +1034,48 @@
 
   ~CommandObjectProcessSignal() override = default;
 
+  void
+  HandleArgumentCompletion(CompletionRequest &request,
+                           OptionElementVector &opt_element_vector) override {
+    if (request.GetCursorIndex() != 0)
+      return;
+
+    const std::map<const char *, const char *> signals = {
+        {"SIGHUP", "hangup"},
+        {"SIGINT", "interrupt"},
+        {"SIGQUIT", "quit"},
+        {"SIGILL", "illegal instruction"},
+        {"SIGTRAP", "trace trap (not reset when caught)"},
+        {"SIGABRT", "abort()"},
+        {"SIGEMT", "pollable event"},
+        {"SIGFPE", "floating point exception"},
+        {"SIGKILL", "kill"},
+        {"SIGBUS", "bus error"},
+        {"SIGSEGV", "segmentation violation"},
+        {"SIGSYS", "bad argument to system call"},
+        {"SIGPIPE", "write on a pipe with no one to read it"},
+        {"SIGALRM", "alarm clock"},
+        {"SIGTERM", "software termination signal from kill"},
+        {"SIGURG", "urgent condition on IO channel"},
+        {"SIGSTOP", "sendable stop signal not from tty"},
+        {"SIGTSTP", "stop signal from tty"},
+        {"SIGCONT", "continue a stopped process"},
+        {"SIGCHLD", "to parent on child stop or exit"},
+        {"SIGTTIN", "to readers process group upon background tty read"},
+        {"SIGTTOU", "to readers process group upon background tty write"},
+        {"SIGIO", "input/output possible signal"},
+        {"SIGXCPU", "exceeded CPU time limit"},
+        {"SIGXFSZ", "exceeded file size limit"},
+        {"SIGVTALRM", "virtual time alarm"},
+        {"SIGPROF", "profiling time alarm"},
+        {"SIGWINCH", "window size changes"},
+        {"SIGINFO", "information request"},
+        {"SIGUSR1", "user defined signal 1"},
+        {"SIGUSR2", "user defined signal 2"}};
+    for (const auto &i : signals)
+      request.TryCompleteCurrentArg(i.first, i.second);
+  }
+
 protected:
   bool DoExecute(Args &command, CommandReturnObject &result) override {
     Process *process = m_exe_ctx.GetProcessPtr();
Index: lldb/test/API/functionalities/completion/TestCompletion.py
===================================================================
--- lldb/test/API/functionalities/completion/TestCompletion.py
+++ lldb/test/API/functionalities/completion/TestCompletion.py
@@ -84,6 +84,13 @@
                               ['mips',
                                'arm64'])
 
+    def test_process_signal(self):
+        self.complete_from_to('process signal ',
+                              'process signal SIG')
+        self.complete_from_to('process signal SIGA',
+                              ['SIGABRT',
+                               'SIGALRM'])
+
     def test_ambiguous_long_opt(self):
         self.completions_match('breakpoint modify --th',
                                ['--thread-id',