I recently spent six weeks in Sydney working for my new job. Naturally, while I was there, I let Google Chrome's omnibox redirect my searches to Google Australia. Fast forward a few weeks, and I'm back in the States, but Chrome is living in the past. After trying just about everything, here is what I finally did to fix it.

First, shut down Google Chrome. Find the Google Chrome default preferences file. On my Mac, that's ~/Library/Application Support/Google/Chrome/Default/Preferences. This is a JSON file. You are looking for an attribute called "last_known_google_url". Mine was set to "https://www.google.com.au/". All I did was change this to "https://www.google.com/".

Good luck!