He is played by Justin Bartha.
Riley Poole is a sarcastic computer expert, resident genius, and best friend of Benjamin Franklin Gates. He tries his hardest to be funny and smart, but doesn't always succeed. He can be nerdy most of the time and get annoyed when people don't listen to him. He loves it when he knows something Ben and Abigail don't.
Riley figured out the clue involving the one hundred dollar bill and Independence Hall. When he realizes that Abigail and Ben do not know what he knows, he takes his time, asking them if this is what they always feel like (much to their anger). Before that Riley tried to convince Ben that stealing the Declaration of Independence was impossible due to the security at the National Archives.
National Treasure: Book of Secrets
Riley later wrote a book, called The Templar Treasure, about treasure hunting and myths. He is shocked when it is not a best seller and people keep confusing him for Ben.
The IRS repossessed his Ferrari because of back taxes at the beginning of National Treasure: Book of Secrets He is brought into the search for Cíbola. To prove Thomas Gates was not part of the plot to kill Abraham Lincoln he and Ben first have to break into Abigail Chases residence since she kicked Ben out. When found out by Abigail she allows them access to the files they need. The clue leads to a Cipher of Edward Laboylee and Riley and Ben are off to Paris France and the French Statue of Liberty. The clue there leads to the Resolute Desk of both the Queen of England and the President of the United States. It is Riley who figures out that the symbol of the two pieces of wood are the Book of Secrets and that leads to the kidnapping by Ben of the President of the United States. The three of them go the Library of Congress where the book is found. It leads to Mount Rushmore (which to Riley's surprise was built as a cover up). After narrowly being killed by several complex traps, they are awed when they reach Cibola, with Riley comically taking several solid gold bricks, making him one of the richest people in North America. Mitchell Wilkinson is there and he forces the five of them including Ben parents to help him find The Lost City of Gold. Originally left to die by Wilkinson and only able to escape because of him, Riley is pleasantly surprised at the return his Ferrari to him tax free by the President. He is also hinted at getting a girlfriend at the end of the second film, as he meets a girl who is fascinated by his book, shocking him (comically causing a large pile of books he is carrying to fall).