Sands had his breakout role as George Emerson in A Room with a View (1985) and went on to appear in The Killing Fields (1984), Gothic (1986), Siesta (1987), Warlock (1989), Arachnophobia (1990), Naked Lunch (1991), Boxing Helena (1993), Leaving Las Vegas (1995), The Medallion (2003), Ocean's Thirteen (2007), and The Girl with the Dragon Tattoo (2011).

His television roles included Nick Hardaway in Rose Red (2002), Vladimir Bierko in 24 (2006), Jor-El in Smallville (2009–2010), and the voice of Valmont in Jackie Chan Adventures (2000–2002).

[8] He was educated at Lord Wandsworth College in Long Sutton, Hampshire, then studied at London's Central School of Speech and Drama.

Following the success of A Room with a View and Ken Russell's Gothic (1986) Sands dropped out of Maurice and decided to move to Hollywood to pursue a career in American films, where he appeared in a range of roles.

In 2002, he starred in Stephen King's Rose Red[14] and the Austrian ambassador Klemens von Metternich in the miniseries Napoléon.

[18][19] In August 2011, he appeared onstage at the Edinburgh Fringe Festival in A Celebration of Harold Pinter, directed by John Malkovich at the Pleasance Courtyard.

[23][24] In 2011, Sands appeared in the mystery thriller film The Girl with the Dragon Tattoo, an English-language remake of the original version, as the younger Henrik Vanger.

According to reports, Sands's mobile phone was last tracked from a pinged location on 15 January, suggesting it had run out of power.

[36] Around the time of his disappearance, Sands was believed to be traversing the Baldy Bowl Trail, "which climbs 3,900 feet (1,200 m) over 4.5 miles (7.2 km) to the highest summit in the San Gabriel Mountains".

[43] On 23 June, the Sands family released a statement saying, "We continue to hold Julian in our hearts with bright memories of him as a wonderful father, husband, explorer, lover of the natural world, and the arts, and as an original and collaborative performer".

[5][46] On 24 July, the cause of death was listed as "undetermined" due to "the condition of the body ... [which is] common when dealing with cases of this type.