In macOS Catalina and macOS Mojave, when an app fails to install because it hasn’t been notarized or is from an unidentified developer, it will appear in System Preferences > Security & Privacy, under the General tab. Click Open Anyway to confirm your intent to open or install the app.

The warning prompt reappears, and you can click Open.*

The app is now saved as an exception to your security settings, and you can open it in the future by double-clicking it, just as you can any authorized app.

*If you're prompted to open Finder: control-click the app in Finder, choose Open from the menu, and then click Open in the dialog that appears. Enter your admin name and password to open the app.

I found the work around as below

1. Open terminal
2. Navigate to path where your chromedriver file is located
3. Execute any one of the below commands

Command1: xattr -d com.apple.quarantine <name-of-executable>

Example

/usr/local/Caskroom/chromedriver 
$ xattr -d com.apple.quarantine chromedriver 

(or)

Command2: spctl --add --label 'Approved' <name-of-executable>

Source: https://docwhat.org/upgrading-to-catalina

Note: This will work only with the file(s) where the above command is executed. If a new chromedriver is downloaded then the command has to be executed again on the newly downloaded file

Open terminal and navigate to path where chromedriver is downloaded. Execute xattr -d com.apple.quarantine chromedriver

Quick solution

1. Open Finder
2. Navigate to where the chromedriver file is located
3. Right-click on the chromedriver file and select open

After this the script should work fine.

The above answers were helpful. I would just add that if you're running Selenium from a development environment, in my case a Jupyter Notebook, and this is the issue, you're likely to see a PermissionError: [Errno 13] Permission denied error. There are other causes for this error, but it can be that macOS Catalina is blocking chromedriver from running for security reasons. Following the approaches above, I ran it from the command line and then was able to open it from Jupyter using driver = webdriver.Chrome('path/to/chromedriver).

Existing answers are great, and they work.

But an easier solution is to open the terminal and run this:

xattr -d com.apple.quarantine $(which chromedriver)

xattr -d com.apple.quarantine $(which chromedriver) alone is not enough.

with the lastest version of chromedriver, it seem like they are dividing into version folders.
for me on 9/30/20. what worked for me is xattr -d com.apple.quarantine 85.0.4183.87/chromedriver

I've found that if you've tried this solution:

// Get the path to chromedriver, example: /usr/local/bin/chromedriver
which chromedriver 

// Change permissions
xattr -d com.apple.quarantine <path_to_chromedriver>

and your browser opens and then immediately closes, it could be from installing the wrong chromedriver version.

Look for your chrome version by launching chrome then selecting

Chrome > About Google Chrome

Remove your current chromedriver and search for the chromedriver that matches your chrome version displayed in your "About Google Chrome" (example: 96.0.4664.110). This worked for me on a mac with the Monterey OS

The easiest way to solve this error, please follow the steps below.

1. Navigate to where your chrome driver application is saved / downloaded
2. Right click and select Open with
3. Select open with Terminal
4. Allow or select yes
5. you should get a success message on the terminal screen
6. Go back to open your chrome driver or on your IDE and run, you should not get the error anymore

1.Navigate to path where your chromedriver file is located 2.right click on the chromedriver 3.open with terminal 4.run ur code

What worked for me on macOS Catalina Version 10.15.6 (19G73) was

1. Install chromedriver via Homebrew:

   brew install chromedriver

2. Then, in Finder click on Go menu and the click Go to folder option, and enter this route:

   /usr/local/Caskroom/chromedriver/

3. There you should see a folder with the chromedriver version you have installed, something like this:

   88.0.4324.96

4. Enter the folder and you should see the chromedriver binary file.

5. Right click on it, and click on Open

Now, you should get a terminal window popping up with the output:

Last login: Sun Jan 31 12:29:15 on ttys001
/usr/local/Caskroom/chromedriver/88.0.4324.96/chromedriver ; exit;
   ~  /usr/local/Caskroom/chromedriver/88.0.4324.96/chromedriver ; exit;
Starting ChromeDriver 88.0.4324.96 (68dba2d8a0b149a1d3afac56fa74648032bcf46b-refs/branch-heads/4324@{#1784}) on port 9515
Only local connections are allowed.
Please see https://chromedriver.chromium.org/security-considerations for suggestions on keeping ChromeDriver safe.
ChromeDriver was started successfully.

Finally, press Ctrl+C to stop the execution and quit the terminal window.

Now, you should be able to run capybara tests.

It was a permission issue... After upgrading chrome this error was showing so I followed the below mentioned steps and it worked in my system.

1. System Preferences
2. Security & Privacy
3. Go to General tab
4. Allow apps downloaded from:
5. Select App Store and identified developers
6. Click the lock to make changes.
7. Enter your system password
8. Click Open Anyway to confirm your intent to open or install the app.

Two steps to solve this:

1. Navigate to the path using command- cd /usr/local/bin . This is where you will see your chromedriver installed.
2. When inside the bin directory, run this command- xattr -d com.apple.quarantine chromedriver .

And that's all. It worked for me like that.

(What worked for me, hopefully works for you too)

Update for all the macOS Big Sur 11.0 users:

1. use homebrew to install chromedriver

   brew install chromedriver

2. navigate to chromedriver that is in the Caskroom folder specifically

   /usr/local/bin/Caskroom/chromedriver ... keep going until you see the Unix Executable File called "chromedriver"

3. following Apple's recommendation for opening Mac apps from unidentified developer, double-click chromedriver, and then click "Open"

For me, this resulted in a terminal window popping up with the output:

Starting ChromeDriver ...
Only local connections are allowed.
Please see https://chromedriver.chromium.org/security-considerations for suggestions on keeping ChromeDriver safe.
ChromeDriver was started successfully.

I can now run scrapy-selenium no problem, you can close the terminal window (yes, terminate the process is OK) and it should still work without stopping you now.

Let me know if this works for you