Grant Grinnell is a certified tennis instructor with the United States Professional Tennis Association.  (USPTA) He is currently instructing at Four Seasons on Maui. Grant is a former #1 Ranked player, has over 55,000 hours on-court experience and is a #1  best selling author for tennis coaching. All Maui visitors are welcome to participate in tennis lessons at Four Season by reserving with Grant. 


“Transformational tennis coach. Brilliant... Can improve your tennis and change your experience with the game. I Highly recommend Grant.” Lori Wartman

"Due to his special talent as an instructor, I have been able to perform at a level I never dreamed possible." Mary Houghes

"We got more out of our first hour with Grant than we had working six months with another instructor" Rick Baxter

"The most up to date ball-striking instruction I have ever experienced. Hands down the most valuable tennis instruction on the planet." Byron Elton

"I feel very fortunate to have had your remarkable expertise, amazing instruction and knowledge. Grant is the tennis whisperer." David Montalba

"Grant is the only one that has made a dramatic, significant difference in his game and his confidence." Peggy Loshin

"The number of aha moments we experienced in those five days was unbelievable. Every facet of our game improved and we had a great time to boot." Brian Williams

"As a former NCAA Division 1 tennis player with numerous coaches throughout my junior, collegiate, and pro career; Grant was able to identify shortcomings in my game quicker than anyone I have worked with in the past. Gabe Davis

"It's a gift and talent that Grant has in abundance. His abilit to recongnize and communicate ways to improve our game is truly amazing"  Hitomi Saheki

Grant is an amazing, gifted instructor." Vikki Littleman

"He has the ability to take a group of players and not miss one small detail."
Debbie Loop

"Grant has made us all believe in ourselves and each other and we had a great season." Pam Pugel

"He helped me add more shots to my game than all my other instructors combined." Lois Mustoned

"Grant is the most talented teacher We've had the pleasure to work with, and we've worked with some very good tennis pros." Rick Morrisse

"His knowledge and commitment is better than any other five star resort I have been to. He is phenomenal." Anton Rabie

"I've taken tennis instruction from resorts all over the world. It is extremely rare to find a teacher with the skill and person of Grant. He was the highlight of my amazing experience." Andrew Ruff

"Grant has a very unique ability unparalleled by any of the coaches we have hired." 
Ed Seeton

"He is the most outstanding instructor I've ever had the privilege to work with." 
Dena Kenedy

"In a short time he was able to solve problems in my game that frustrated me for years. In my past coaching career I observed many successful college and olympic coaches; Grant is by far one of the best instructors and communicators I have experienced." Doris Glaz

"I have played tennis, coached tennis, and generally enjoyed the game for over 35 years. From my point of view, Grant is one of the best instructors of the game I have encountered. He is a rare combination of effective teacher and encourager." 
Steve Charleston

"He is dependable, always on time and always has a smile on his face. He is truly the best instructor I have ever had. His passion for the game and people is evident in everything he does." Kim Vaughn.

"Grant is the finest coach I have encountered in the world. Four Seasons is fortunate to have him." Sarah Hunter

"His teaching style is powerful, direct and produces results." Michelle Seidl

Grant Grinnell has spent his entire professional life dedicated to developing the most effective and efficient methods to helping athletes find their best fast.  I have personally benefited as a current 6.0 tennis player, and as a full time coach more from Grant's methods than all of my other resources put together.  I estimate that Grant's teachings have fast forwarded my knowledge base and instructional abilities ten years, and frankly I may have never reached the level I feel I am currently without Grant's help. Jesse Schouten

"You're amazing! In ten years of taking tennis lessons, I haven't found anyone that can come close to your teaching style. Thanks for making my Maui trip so special.. All those glowing testimonials on your website were absolutely right on... Grant is the Greatest." Eliana Brooke