@@ -17772,8 +17772,8 @@ impl fmt::Display for CreateWarehouse {
 pub struct AlterUser {
     /// Whether to only alter the user if it exists.
     pub if_exists: bool,
-    /// The name of the user to alter.
-    pub name: Ident,
+    /// The name of the user to alter, or the current user when omitted.
+    pub name: Option<Ident>,
     /// Optional new name for the user (Snowflake-specific).
     /// See: <https://docs.snowflake.com/en/sql-reference/sql/alter-user#syntax>
     pub rename_to: Option<Ident>,
@@ -17929,7 +17929,9 @@ impl fmt::Display for AlterUser {
         if self.if_exists {
             write!(f, " IF EXISTS")?;
         }
-        write!(f, " {}", self.name)?;
+        if let Some(name) = &self.name {
+            write!(f, " {name}")?;
+        }
         if let Some(new_name) = &self.rename_to {
             write!(f, " RENAME TO {new_name}")?;
         }
 
@@ -150,7 +150,33 @@ impl Parser<'_> {
     /// ```
     pub fn parse_alter_user(&mut self) -> Result<AlterUser, ParserError> {
         let if_exists = self.parse_keywords(&[Keyword::IF, Keyword::EXISTS]);
-        let name = self.parse_identifier()?;
+        let action_keywords = [
+            Keyword::RENAME,
+            Keyword::RESET,
+            Keyword::ABORT,
+            Keyword::ADD,
+            Keyword::REMOVE,
+            Keyword::ENROLL,
+            Keyword::MODIFY,
+            Keyword::SET,
+            Keyword::UNSET,
+        ];
+        let next_is_action = matches!(
+            &self.peek_nth_token_ref(1).token,
+            Token::Word(word)
+                if action_keywords.contains(&word.keyword) || word.keyword == Keyword::WITH
+        );
+        let at_end = matches!(self.peek_nth_token_ref(1).token, Token::EOF | Token::SemiColon);
+        let name = if action_keywords
+            .iter()
+            .any(|keyword| self.peek_keyword(*keyword))
+            && !next_is_action
+            && !at_end
+        {
+            None
+        } else {
+            Some(self.parse_identifier()?)
+        };
         let _ = self.parse_keyword(Keyword::WITH);
         let rename_to = if self.parse_keywords(&[Keyword::RENAME, Keyword::TO]) {
             Some(self.parse_identifier()?)
 
@@ -19372,13 +19372,35 @@ fn parse_create_index_different_using_positions() {
 #[test]
 fn test_parse_alter_user() {
     let dialects = all_dialects_except(|d| d.supports_alter_user_as_alter_role());
+    for action in ["SET QUERY_TAG='self-target-tag'", "UNSET QUERY_TAG"] {
+        for modifier in ["", "IF EXISTS "] {
+            let statement = dialects.verified_stmt(&format!("ALTER USER {modifier}{action}"));
+            let Statement::AlterUser(alter_user) = statement else {
+                unreachable!()
+            };
+            assert_eq!(alter_user.name, None);
+            assert_eq!(alter_user.if_exists, !modifier.is_empty());
+        }
+        for name in [
+            "SET", "UNSET", "RENAME", "RESET", "ABORT", "ADD", "REMOVE", "ENROLL", "MODIFY",
+            "WITH", "PASSWORD", "ENCRYPTED",
+        ] {
+            dialects.verified_stmt(&format!("ALTER USER {name}"));
+            let statement = dialects.verified_stmt(&format!("ALTER USER {name} {action}"));
+            let Statement::AlterUser(alter_user) = statement else {
+                unreachable!()
+            };
+            assert_eq!(alter_user.name, Some(Ident::new(name)));
+            dialects.verified_stmt(&format!("ALTER USER \"{name}\" {action}"));
+        }
+    }
     dialects.verified_stmt("ALTER USER u1");
     dialects.verified_stmt("ALTER USER IF EXISTS u1");
     let stmt = dialects.verified_stmt("ALTER USER IF EXISTS u1 RENAME TO u2");
     match stmt {
         Statement::AlterUser(alter) => {
             assert!(alter.if_exists);
-            assert_eq!(alter.name, Ident::new("u1"));
+            assert_eq!(alter.name, Some(Ident::new("u1")));
             assert_eq!(alter.rename_to, Some(Ident::new("u2")));
         }
         _ => unreachable!(),