Robert Whitlock Alley (born December 30, 1955) is an American writer and illustrator of children’s books. He is best known for illustrating the children’s literature series Paddington Bear.

Alley was born on December 30, 1955 in Lexington, Virginia to Helene Whitlock and Dr. Reuben Alley, Jr. He grew up in Annapolis, Maryland where his father was a civilian professor of electrical engineering at the United States Naval Academy.

Alley studied Art History at Haverford College and graduated in 1979.

He spent his early career illustrating greeting cards for multiple companies, including Hallmark Cards.

He published his first book, The Ghost in Dobbs Diner, in 1981.

He met author Michael Bond in 1997 and after an audition began illustrating the Paddington Bear book series. He illustrated Bond's final book, Paddington at Saint Paul's, in 2018, and has illustrated more than 20 books in the series as of 2024. He is the longest-serving Paddington Bear illustrator.

In 2016, he appeared on the baking competition show Cake Wars, in the Season 4 episode, "Paddington".

Alley lives in Barrington, RI with his wife, Zoe.  They have two children.