José Antonio Marton
São Paulo
One of the most successful designers in Brazil, Marton began to collect in 1990, when a friend gave him a Renina Katz painting, “Os Retirantes,” as payment for a job. In 1995, with his brother Fernando, he founded Marton+Marton, a firm dedicated to design, architecture, and art projects. Every month the company advises an average of 30 to 50 artists. Most of the 400 or so works in Marton’s collection are by artists who launched their careers in the 1980s and ’90s. “My focus has always been Brazilian artists like Vik Muniz, Ernesto Neto, Rosângela Rennó, Valeska Soares, Marcelo Cidade, Marcius Galan, and Ana Tavares, among others,” Marton says. That’s not to say his collection stays within national boundaries — he also owns work by Anselm Kiefer, José Pedro Croft, and Charles Long.

Andreas Melas
Athens
A dealer as well as a collector, Melas began his career at Deitch Projects, in New York, before branching out with Andreas Melas Presents, in its initial manifestation as a project, and then as a bona fide exhibition space in Athens. In 2011 Melas joined up with Helena Papadopoulos (of Berlin’s Nice and Fit) on their eponymous Greek gallery. Melas’s collection includes work by Sterling Ruby, Martin Boyce, Cyprien Gaillard, Urs Fischer, and Joe Bradley.

Jillian Murphy
New York
While working at C24 Gallery and also acting as co-director of the independent migratory curatorial organization AD Projects, Murphy finds time to add to a personal art collection that she began around 2006. That year she was given a Gary Simmons painting, “Untitled #1 (Study for Marnie’s Room).” “It definitely shaped the direction for my collection,” she says, “as it’s aesthetically beautiful but also inherently disastrous. Everything I have collected since is both beautiful and chaotic.”

Valeria Napoleone
London
Napoleone, married to a banker and the mother of three, collects art exclusively by women. With well over 200 pieces — paintings, sculpture, photography, film, video, and installations — her collection includes work by Shirin Neshat, Ghada Amer, Joanne Greenbaum, Nina Canell, and others. She has been a judge for the MaxMara Art Prize for Women and chairs the development committee at the nonprofit Studio Voltaire.

Alden and Janelle Pinnell
Dallas
Texas collectors are known to have a penchant for glamour, but Alden Pinnell is cut from different cloth. The 41-year-old cosmetics magnate is just as likely to be spotted in jeans, cooking a whole roasted pig alongside artist Virginia Overton at his kunsthalle-like art space, the Power Station, as he is chairing a high-profile charity art auction. Alden’s boundary-breaking spirit is the driving force behind his art space, which opened a year and a half ago in a sprawling former Dallas Power and Light warehouse.

Since then, the Power Station has hosted ambitious installations by Overton, Matias Faldbakken, Oscar Tuazon, and Jacob Kassay. “The Power Station allows artists to make work outside the white cube,” says Alden. “Not all art is collectible.” Which isn’t to say he doesn’t collect. Though he never displays his collection at the Power Station, Alden and his wife, Janelle, have been quietly assembling some 200 pieces of contemporary art over the last decade with the help of art adviser (and Power Station board member) Rob Teeters. As their kunsthalle demonstrates, the Pinnells eschew showy, Pop-inflected pieces for a more contemplative aesthetic. Work by artists like Mark Manders, Michaël Borremans, Lucas Samaras, and Nigel Cooke fill their home. “The art that we like the best in our collection isn’t too seductive,” Alden says. “It’s like music: The songs you don’t understand immediately are the ones you are still listening to 20 years later.” — Julia Halperin