He has a hobby of collecting

Morgan was an avid collector of books, photographs, artwork, timepieces, and other works of art. Many of these items were lent or donated to the Metropolitan Museum of Art, whose founding he played a significant role in as president, and many others were kept in his London residence and private library on 36th Street, close to Madison Avenue in New York City.

British artist and critic Roger Fry served as a collector for the museum and Morgan for several years. As a tribute to his father, J.P. Morgan Jr. established the Pierpont Morgan Library as a public space in 1924. He retained Belle da Costa Greene, his father's librarian, as the library's first director.

Morgan has also developed into one of the most significant American gem collectors and has put together the most significant collection of both American and jewels (more than 1,000 pieces). Under the supervision of George Frederick Kunz, Tiffany & Co.'s Chief Gemologist, the company put together its initial collection. The collection was displayed at the 1889 Paris World's Fair. Two gold prizes were given to the exhibition, which also caught the interest of notable academics, researchers, and members of the public.