Smith has worked on the English writing of more than 30 Nintendo titles since 2009, including Mario & Luigi: Dream Team, Luigi’s Mansion: Dark Moon and Paper Mario: Color Splash.
Smith was also a regular on Nintendo’s E3 Treehouse live streams.
“After 10 incredible years with the company, I’ve decided to leave Nintendo. Yesterday was my last day,” he wrote on Twitter.
“Working at Nintendo has been the opportunity of a lifetime, and I’ll miss working alongside all of the lifelong friends I’ve made there.
“The Treehouse is full of many writers more talented than I, and I can’t wait to see what they do in the future.”
He added: “Writing for the Splatoon series has been one of the greatest joys of my life. Having written nearly every English word ever spoken by Pearl, Marina, Callie, and Marie, it’s really hard to walk away from them, and I’m going to miss my girls dearly.
“The Paper Mario series is one of the reasons I wanted to work at Nintendo in the first place, so being the lead writer on Paper Mario: Color Splash was a dream come true. I’m very proud of the writing in this game.”
According to NPD Group, Super Mario Maker 2 set a new record high for launch month sales of a Mario Maker title, surpassing both the September 2015 release of Super Mario Maker and the December 2016 release of Super Mario Maker 3DS.