In the early 1990s, Mellor won drawing prizes at the ANU's Canberra School of Art and the
Grafton Regional Gallery in New South Wales. Through the mid-1990s, while studying in Canberra and Birmingham, he was represented in numerous student and other exhibitions, in Australia, Belgium, Japan, Korea and the United Kingdom. These included exhibitions titled
Passage, at
Kyoto Seika University in Japan in 1994, and
Fragile Objects at the
National Library of Australia in 1996. Subsequent entries have included
Of fragile dreams the heart which nevermore in 2005,
Untitled (Ernie Grant in Blackman Street) in 2006,
Exotic lies and sacred ties (the heart that conceals, the tongue that never reveals) in 2008, and
A Transcendent Vision (of life, death and resurrection) in 2010. Reviewing the 2008 exhibition, academic Sarah Scott expressed surprise that Mellor's 2008 piece had neither attracted an award nor been purchased for the Northern Territory's public collection. He has had numerous other exhibitions, both individually and as part of group shows, at galleries including the Queensland Art Gallery in 2003, the Canberra Museum and Art Gallery in 2006, and the Indigenous Ceramic Art Awards, at Shepparton Gallery in Victoria in 2007. The work featured in media reports of the exhibition, including by
The Adelaide Advertiser,
The Canberra Times,
The West Australian and the
Australian Broadcasting Corporation. Since graduating, Mellor has won several awards, including the Canberra Critic's Choice Award in 2006, and the $15,000 John Tallis National Works on Paper Acquisitive Award in 2008. The following year, he won the Victorian Indigenous Ceramic Art Award, held at Shepparton Art Gallery in
Shepparton, Victoria. In August 2009, Mellor won the AU$40,000 National Aboriginal & Torres Strait Islander Art Award, for his mixed media work
From Rite to Ritual. It was only the third time in the award's 26 years that an urban Aboriginal artist had been the winner. Earlier that year his solo show at Brisbane's Jan Murphy Gallery had sold out. Also in that year, Mellor's work was featured alongside that of
Patricia Piccinini and
Cherry Hood in the Newcastle Region Art Gallery's show
Animal Attraction. Though Mellor has not had a painting hung in the
Archibald Prize, he was the subject of Paul Ryan's portrait that was a 2010 finalist in that competition. In 2012, his work was included in the
National Museum of Australia's exhibition
Menagerie: Contemporary Indigenous Sculpture, and in the second National Indigenous Art Triennial. He was also selected for inclusion in that year's
Blake Prize, with his work
Bulluru Storywater. Mellor received international recognition in 2013, when he was included in
Sakahàn, the National Gallery of Canada's "most ambitious contemporary art exhibition in its history". Among the national collections containing Mellor's work are the
National Gallery of Australia, which owns his prize-winning
From Rite to Ritual, and the
Parliament House Art Collection. and Warrnambool Art Gallery in Victoria. as well as in large, private collections such as the Kerry Stokes. In 2011, Mellor was not an entrant in the National Aboriginal & Torres Strait Islander Art Award, as he instead became one of its judges. Appointed to the Visual Arts Board for a further term, Mellor in 2013 became its Chair. At the same time, Mellor continued to exhibit works. In 2014, a survey of his works opened at the
University of Queensland Art Museum and was scheduled to travel to the Museum and Art Gallery of the Northern Territory later in the year. The exhibition was favourably reviewed in
theguardian.com, with art critic Sharne Wolff drawing attention to Mellor's newest sculpture,
Anima, which she said "marks a dramatic change" for the artist, bearing "no resemblance to Mellor’s more glamorous output". His work featured as part of the
Edinburgh International Festival, with a show titled
Primordial: SuperNaturalBayiMinyjirral displayed at the
National Museum of Scotland. A large work of Mellor's,
Entelekheia (2016), consisting of photographic images of plants etched in concrete, can be found on the exterior walls of the
International Convention Centre in Sydney. ==Technique and themes==