|Age:||52 ( estimated)|
|Family:|| Grandpa Spencer (father)|
Henry Spencer (brother)
Madeleine Spencer (former sister-in-law)
Shawn Spencer (nephew)
|Aliases:|| Uncle Jack|
|First appearance:||The Greatest Adventure in the History of Basic Cable|
|Last appearance:||The Greatest Adventure in the History of Basic Cable|
Jacob "Jack" Spencer is Henry Spencer's younger brother and Shawn Spencer's uncle. He is a "treasure hunter" and cheats people out of money, even his own family. His redeeming feature, beyond his charm and zeal, seems to be that he takes losing in his stride, and is even impressed when his nephew outplays him. He is portrayed by Steven Weber.
He appears in The Greatest Adventure in the History of Basic Cable where he convinced Shawn and Gus to help him find treasure, but was actually planning on keeping all the money for himself. He promised to split the cash with many different people along the way so they'd help him, but he planned on keeping it for himself all along. He had Shawn throw what he thought was the bag of treasure in his car, then sped away and ditched Shawn and Gus, but when he pulled over to look at his loot he found that the bag was just filled with rocks, and a single penny (which was Jack's trademark, to leave pennies at different places he was). Jack was frustrated, yet proud of Shawn that he pulled off the con on him.
However, perhaps because he was outplayed, Jack doesn't show up, or even get mentioned, again.