Josh Wolowitz is Howard Wolowitz's younger half-brother. In "The Fortification Implementation", Howard meets Josh, his father's son from a second family, for the first time. Josh is an oceanography student from San Diego who learned about Howard after his mother's lawyers contacted him. He has a similar warped personality as Howard had before he met Bernadette. He understands about the robot arm that Howard used for self-gratification. Howard hugs him knowing that he is really his brother. Josh also thinks it's neat that his half-brother is an astronaut.
Josh first appears in "The Fortification Implementation" at Howard's late mother's house which he and Bernadette had moved into. He tells Howard how a lawyer contacted his father, Sam Wolowitz, about the title on that house. Since Sam was Howard's father, that makes the young man, Howard's half-brother. Howard calls and tells Bernadette that weird things were happening. Howard runs off to get more coffee leaving Josh with Bernadette and Raj. He is an oceanography student in San Diego; while Bernadette loves "Finding Nemo". Raj challenges him as to who he really is though who would still claim to be a Wolowitz? Does he want money, a kidney or for Howard to replace his father as Ringo in a Beatles' cover band? Bernadette sends him after Howard. Howard is upset that Josh shows up and that his father has another family. Howard wants to tell Josh to leave until Josh exclaims how amazing that his brother is an astronaut, that it's amazing and asks what it was like. Raj tries to tell Josh that it's time for him to hit the road, but Howard cuts him off saying "Whoa, hey, hey. The young man asked a good question.". Howard starts to explain about the greatest adventure of his life. Howard is entertaining Josh with magic which he finds pretty cool until he figures he has to go. Howard hopes to see him again. Josh has always dreamed to have someone to play catch and Bernadette tells him that he'll have to keep dreaming. Howard mentions using the robot to do it, and Josh thinks he means sex. But at the door, Howard tells Josh that it was actually just a mechanical hand. Josh thinks that that is all he needs. Howard hugs him telling Josh that he is definitely his brother.
- Father: Sam Wolowitz
- Mother: Mrs. Wolowitz II
- Half-Brother: Howard Wolowitz
- Half-Sister-in-law: Bernadette Rostenkowski-Wolowitz
- Half-Niece: Halley Wolowitz