They're both big and strong, and they both hit it far. But most of us can still tell them apart.
Not the first-tee announcer at East Lake, though. In a "can-I-have-a-Mulligan" moment during the final round of the Tour Championship, she introduced Henrik Stenson as Dustin Johnson.
You can watch the video of the slip-up above. For more news that golfers everywhere are talking about, follow @si_golf on Twitter, like us on Facebook, and subscribe to our YouTube video channel.