Brisbane, located within the South East Queensland biogeographic region, is renowned for its rich ecological diversity, showcasing a wide array of flora and fauna. Among the city’s most iconic trees are the majestic jacarandas, which burst into bloom with vibrant purple flowers each October, lining many avenues and parks. These subtropical trees, native to South America, stand alongside the Moreton Bay fig, an evergreen banyan known for its large buttress roots, often illuminated with decorative lights during festive seasons in the inner city.

In addition to jacarandas and Moreton Bay figs, the metropolitan area is home to various other tree species, including the Moreton Bay chestnut, broad-leaved paperbark, poinciana, weeping lilli pilli, and Bangalow palm. Along the banks of the Brisbane River and Moreton Bay, mangrove wetlands provide critical habitats for diverse wildlife. The red poinsettia was historically recognized as Brisbane's official floral emblem, though it originates from Central America. In 2023, the Brisbane wattle, a native species, was added as an additional floral emblem, emphasizing the city's commitment to celebrating its local biodiversity.

Brisbane is a sanctuary for numerous bird species, with vibrant rainbow lorikeets, kookaburras, galahs, Australian white ibises, and the familiar sounds of Australian magpies and noisy miners commonly gracing the urban landscape. The city’s parks and backyards are also home to various reptiles, including common garden skinks, Australian water dragons, bearded dragons, and blue-tongued lizards. Among the mammalian residents, common ringtail possums and flying foxes thrive, while colorful butterflies like the common crow and blue triangle flutter through gardens.

The Brisbane River is a thriving ecosystem that supports a variety of fish species, such as yellowfin bream, flathead, Australasian snapper, and even bull sharks. Moreton Bay's waters host a rich marine life, including dugongs, humpback whales, dolphins, mud crabs, soldier crabs, and numerous shellfish species.

Notably, the koala and graceful tree frog have been designated as the official faunal emblems of Brisbane. However, both species are increasingly threatened by urban development and the impacts of climate change. The city faces significant ecological challenges as it strives to balance urban growth with environmental conservation. As Brisbane continues to evolve, efforts to protect and preserve its unique biodiversity remain crucial for maintaining the health of its ecosystems for future generations.