Fortt joins running back Silas Redd and tight end Kevin Haplea as players to leave the Nittany Lions in the last two days in the wake of the Jerry Sandusky child sex abuse scandal. Several Penn State players, including linebacker Michael Mauti and defensive lineman Jordan Hill, said last week they are staying.
"Basically I wanted to take a leap of faith and trust in God," Fortt told the Stamford Adocate."This is what's right for me and my family. ... The way you go through life is the way you handle adversity. The friends I've made here are friends."
Fortt is eligible to transfer immediately without sitting out a season after Penn State was hit with unprecedented sanctions two weeks ago, including a four-year bowl ban.
Fortt, a junior who will have two years of eligibility remaining, was expected to battle for the Nittany Lions' starting middle linebacker spot this fall. His father said his son has had between 30 and 40 schools contact him since the NCAA announced severe sanctions on the program.
Cal coach Jeff Tedford said in a statement that the Golden Bears "are excited to welcome" Fortt "to the Cal family."
An ESPN 150 recruit and a U.S. Army All-America selection out of high school in Stamford, Conn., Fortt has seen action in 23 games for the Nittany Lions, racking up 50 tackles, including seven for a loss. Last season, he posted 33 tackles, six for loss and 2.5 sacks.
Penn State freshman defensive lineman Jamil Pollard will transfer to Rutgers, his high school coach said Wednesday.
Information from ESPN RecruitingNation's Kipp Adams was used in this report.