In September 2014, Higgins released her fourth studio album, Oz, which features cover versions of Australian composers, including The Angels, Slim Dusty, Something For Kate, Warumpi Band, Paul Kelly and The Drones. The album is also accompanied by a book of related essays, in which Higgins uses each of the recordings to reflect upon subjects such as music and love. Higgins collaborated with Dan Sultan for the recording of the Slim Dusty song "The Biggest Disappointment".
The national Australian tour in support of Oz commenced on 20 September 2014 in Cairns, Queensland, and ended in Melbourne in October 2014. Higgins was accompanied by Bischoff, and Australian artist Dustin Tebbutt appeared as a special guest.
In response to the proposed dumping of around 3 million cubic metres (110 million cubic feet) of dredged seabed onto the Great Barrier Reef, a legal fighting team was formed by World Wide Fund for Nature (WWF)-Australia and the Australian Marine Conservation Society (AMCS) in late 2013/early 2014. The legal team received further support in April 2014, following the release of the "Sounds for the Reef" musical fundraising project. Produced by Straightup, the digital album features Higgins, in addition to artists such as The Herd, Sietta, John Butler, The Cat Empire, Fat Freddys Drop, The Bamboos (featuring Kylie Auldist) and Resin Dogs. Released on 7 April, the album's 21 songs were sold on the Bandcamp website.