It is a chance for fans of the orange and black to mingle with one another, get autographs and hear from the some of their favorite players.
Hunter Pence, who just rejoined the team, was among those who showed up.
Also in attendance was rapper E-40, he is getting his own bobblehead night this season. It will be on July 10 against the San Diego Padres.
For fans it was like being a kid in a candy store.
They got to wander around the stadium and set foot on the field as well which for many was the highlight of the day.
"Being on the field is something I never thought I could experience, being in the dugout too. So cool," said Aaron Vega of Belmont. "This is the time for everybody to enjoy their inner child, embrace what we call baseball, and like, we all come together for the sport and we all support a team."
The Giants will begin Spring Training in Arizona on Tuesday.
Their first official game is March 26 in Los Angeles against the Dodgers and the home opener will also be against the Dodgers, it's on April 3.