diff --git a/crates/dbx-core/src/agent_connection.rs b/crates/dbx-core/src/agent_connection.rs
index 5aa9672f5..9b5475ea4 100644
--- a/crates/dbx-core/src/agent_connection.rs
+++ b/crates/dbx-core/src/agent_connection.rs
@@ -59,6 +59,7 @@ pub fn agent_connect_params(config: &ConnectionConfig, host: &str, port: u16, da
         "ca_cert_path": config.ca_cert_path,
         "client_cert_path": config.client_cert_path,
         "client_key_path": config.client_key_path,
+        "connect_timeout_secs": config.effective_connect_timeout_secs(),
         "etcd_endpoints": etcd_endpoints,
         "zookeeper_connect_string": zookeeper_connect_string,
         "gbase_server": config.gbase_server,
@@ -734,6 +735,16 @@ mod tests {
         assert_eq!(params["connection_timeout_ms"], 20_000);
     }
 
+    #[test]
+    fn agent_params_include_effective_connect_timeout_seconds() {
+        let mut cfg = config(DatabaseType::Mysql, Some("app"));
+        cfg.connect_timeout_secs = 45;
+
+        let params = agent_connect_params(&cfg, "mysql.example.com", 3306, "app");
+
+        assert_eq!(params["connect_timeout_secs"], 45);
+    }
+
     #[test]
     fn zookeeper_agent_params_fall_back_to_host_port_connect_string() {
         let cfg = config(DatabaseType::ZooKeeper, None);
diff --git a/plugins/jdbc/manifest.json b/plugins/jdbc/manifest.json
index d19a48d6d..5f45506a0 100644
--- a/plugins/jdbc/manifest.json
+++ b/plugins/jdbc/manifest.json
@@ -1,7 +1,7 @@
 {
   "id": "jdbc",
   "name": "DBX JDBC Plugin",
-  "version": "0.1.24",
+  "version": "0.1.25",
   "protocol_version": 1,
   "description": "Adds optional JDBC driver support to DBX.",
   "executable": "bin/dbx-jdbc-plugin",
diff --git a/plugins/jdbc/pom.xml b/plugins/jdbc/pom.xml
index 88ad74a77..92607fdfb 100644
--- a/plugins/jdbc/pom.xml
+++ b/plugins/jdbc/pom.xml
@@ -4,7 +4,7 @@
   <modelVersion>4.0.0</modelVersion>
   <groupId>app.dbx</groupId>
   <artifactId>dbx-jdbc-plugin</artifactId>
-  <version>0.1.24</version>
+  <version>0.1.25</version>
 
   <properties>
     <maven.compiler.source>17</maven.compiler.source>
diff --git a/plugins/jdbc/src/main/java/app/dbx/jdbc/DbxJdbcPlugin.java b/plugins/jdbc/src/main/java/app/dbx/jdbc/DbxJdbcPlugin.java
index a099e95c6..43381f200 100644
--- a/plugins/jdbc/src/main/java/app/dbx/jdbc/DbxJdbcPlugin.java
+++ b/plugins/jdbc/src/main/java/app/dbx/jdbc/DbxJdbcPlugin.java
@@ -554,7 +554,36 @@ public final class DbxJdbcPlugin {
         }
         String value = Integer.toString(connectTimeoutSecs);
         properties.putIfAbsent("loginTimeout", value);
-        properties.putIfAbsent("connectTimeout", value);
+        if (!jdbcUrlHasParameter(jdbcUrl(connection), "connectTimeout")) {
+            properties.putIfAbsent("connectTimeout", connectTimeoutPropertyValue(connection, connectTimeoutSecs));
+        }
+    }
+
+    private static String connectTimeoutPropertyValue(JsonNode connection, int connectTimeoutSecs) {
+        if (usesMillisecondConnectTimeout(connection)) {
+            return Integer.toString(connectTimeoutSecs * 1000);
+        }
+        return Integer.toString(connectTimeoutSecs);
+    }
+
+    private static boolean usesMillisecondConnectTimeout(JsonNode connection) {
+        String url = jdbcUrl(connection);
+        if (
+            urlMatchesPrefix(url, "jdbc:mysql:") ||
+            urlMatchesPrefix(url, "jdbc:mariadb:") ||
+            urlMatchesPrefix(url, "jdbc:starrocks:") ||
+            urlMatchesPrefix(url, "jdbc:doris:")
+        ) {
+            return true;
+        }
+        String driverClass = optionalText(connection, "jdbc_driver_class");
+        if (driverClass == null) {
+            return false;
+        }
+        String normalized = driverClass.toLowerCase(Locale.ROOT);
+        return normalized.equals("com.mysql.cj.jdbc.driver") ||
+            normalized.equals("com.mysql.jdbc.driver") ||
+            normalized.equals("org.mariadb.jdbc.driver");
     }
 
     private static boolean isPrestoOrTrinoConnection(JsonNode connection) {
@@ -2396,6 +2425,13 @@ public final class DbxJdbcPlugin {
     }
 
     private static boolean urlHasQueryParam(String url, String key) {
+        return jdbcUrlHasParameter(url, key);
+    }
+
+    private static boolean jdbcUrlHasParameter(String url, String key) {
+        if (url == null) {
+            return false;
+        }
         int queryStart = url.indexOf('?');
         if (queryStart < 0) {
             return false;
diff --git a/plugins/jdbc/src/test/java/app/dbx/jdbc/DbxJdbcPluginTest.java b/plugins/jdbc/src/test/java/app/dbx/jdbc/DbxJdbcPluginTest.java
index 494d1178d..ab9bb5b72 100644
--- a/plugins/jdbc/src/test/java/app/dbx/jdbc/DbxJdbcPluginTest.java
+++ b/plugins/jdbc/src/test/java/app/dbx/jdbc/DbxJdbcPluginTest.java
@@ -485,6 +485,43 @@ final class DbxJdbcPluginTest {
         assertEquals("45", properties.getProperty("connectTimeout"));
     }
 
+    @Test
+    void mysqlConnectTimeoutSecondsAreMappedToMilliseconds() throws Exception {
+        Method method = DbxJdbcPlugin.class.getDeclaredMethod("applyConnectTimeout", JsonNode.class, Properties.class);
+        method.setAccessible(true);
+        Properties properties = new Properties();
+        JsonNode connection = MAPPER.readTree("""
+            {
+              "connection_string": "jdbc:mysql://ddb.example.test:6000/app",
+              "jdbc_driver_class": "com.mysql.cj.jdbc.Driver",
+              "connect_timeout_secs": 45
+            }
+            """);
+
+        method.invoke(null, connection, properties);
+
+        assertEquals("45", properties.getProperty("loginTimeout"));
+        assertEquals("45000", properties.getProperty("connectTimeout"));
+    }
+
+    @Test
+    void explicitJdbcUrlConnectTimeoutIsNotOverridden() throws Exception {
+        Method method = DbxJdbcPlugin.class.getDeclaredMethod("applyConnectTimeout", JsonNode.class, Properties.class);
+        method.setAccessible(true);
+        Properties properties = new Properties();
+        JsonNode connection = MAPPER.readTree("""
+            {
+              "connection_string": "jdbc:mysql://ddb.example.test:6000/app?connectTimeout=5000",
+              "connect_timeout_secs": 45
+            }
+            """);
+
+        method.invoke(null, connection, properties);
+
+        assertEquals("45", properties.getProperty("loginTimeout"));
+        assertFalse(properties.containsKey("connectTimeout"));
+    }
+
     @Test
     void jdbcxHighPrivilegeExtensionsAreDisabledByDefault() throws Exception {
         Method method = DbxJdbcPlugin.class.getDeclaredMethod(