Lleyton, 38, and 10-year-old Cruz are both dressed in tennis whites - the traditional Wimbledon dress code, which dates back to 1877.
Cruz looked like he had a fun day out with his dad, and posted pics from the day to his own social media account, including one snap of him smiling from the umpire's chair.
Bec and Lleyton are enjoying the northern hemisphere summer with their children, Cruz, 10, Mia, 13 and 8-year-old Ava.