No venue has yet been announced for the bout, which is Pacquiao's first since a one-sided victory over Adrien Broner in January, Sky Sports reported.
Thurman, who is undefeated in 29 fights, beat Josesito Lopez in his most recent fight, also in January. That followed a 22-month injury layoff following elbow surgery.
After his win over Lopez, Thurman discussed a fight against Pacquiao, saying, "Manny Pacquiao is not going to be here for the years to come. Just fighting a legend, I just feel like the clock is ticking.
"Later this year if that fight presents itself, I would definitely be open for negotiations and I would love an opportunity to fight a legend.
"He's not the young Manny Pacquiao that he once was but he still is a great, world-class fighter. If we get that fight, we'd be happy to do it for ourselves and the fans."
Pacquiao is 61-7-2 during his 24-year boxing career, and currently holds the WBA (Regular) belt.
Thurman, from Florida, the US, has wins over Danny Garcia and Shawn Porter to his name.