The Frazer Mausoleum, once the resting place of the Frazer family, is the largest and most iconic monument in Rookwood Necropolis, and a one-of-a-kind structure in Australia. John Frazer was an Irish-born merchant, company director and philanthropist who arrived in Sydney in 1842 as a bounty immigrant. He ran several businesses, with John Frazer & Co. becoming one of the most influential mercantile houses in Sydney.

John and Elizabeth Frazer commissioned Maurice B. Adams to design the mausoleum, built in 1894 for £5,000 (approximately $1 million in 2024 currency). The building is constructed from Pyrmont Sandstone known as "Yellowblock", which deepens to a honey-yellow colour as it oxidises with age. The architecture was described as "high Victorian Byzantine Gothic" with a dome of Byzantine or Moorish influence and gargoyles of French influence.

Throughout the 1960s, there was considerable vandalism throughout Rookwood. As a result, the Frazer family decided to have those who were interred in the mausoleum cremated.

In 2024, the Frazer Mausoleum underwent restoration, in collaboration with the Friends of Rookwood. Restoration works included desalinating the stonework, repointing open joints, replacing missing stained-glass windows, weather-proofing the dome, installing protective bronze mesh grills, and reconstructing the three alabaster sarcophagi to preserve the mausoleum's rich heritage.