Founder Bruce Poon Tip is looking for the tourists – thought to be named Ivan and Hayley – in an effort to educate them to be more conscious travellers.
It comes after a video went viral on social media earlier this week of a man carving "Ivan+Hayley 23" into the wall of the ancient monument.
Should they be found, Poon Tip has invited the duo to travel with the company to GX, G Adventures’ inaugural annual community travel summit in Peru, with a "reward trip" also being offered to the event for any one person who assists in reaching them.
"While it’s shocking to see anyone deface an ancient landmark like the Colosseum, it’s not as uncommon as many would think," Poon Tip said.
"Rather than condemning Ivan and Hayley, I’m launching an appeal to find them, and to invite them to GX, G Adventures’ inaugural annual community travel summit, which is taking place in September in Peru."