The 26-year-old Japanese collected 14 top-10 finishes last year on Japan Golf tour and in October won his second career title at the Bridgestone Open where he birdied the final three holes to win by one shot.
His other win came at the 2017 Kansai Open Golf Championship, winning by six strokes.
For Imahira, who is ranked 53rd in the world rankings, his appearance at Augusta National Golf Club for the April 11-14 Masters will mark his first appearance at the year's opening major.
"Bobby Jones and Clifford Roberts established the Masters as a global sporting event, so throughout our history special invitations for deserving international players have always been carefully considered," Fred Ridley, Chairman of Augusta National Golf Club, said in a statement.
"We are pleased to continue this tradition by welcoming Shugo Imahira to our field this year based on his impressive record during the past 12 months."
The field for the Masters stands at 80 players and the only remaining ways to qualify are by winning a PGA Tour event that awards a full-point allocation for the season-ending Tour Championship or by finishing among the top 50 in the world rankings published during the week prior to the Masters.
(Reporting by Frank Pingue in Toronto, editing by Pritha Sarkar)