About 20 National Gallery of Australia staff were told on Friday September 16 their jobs would not exist on Monday.
The gallery's deputy director, Kirsten Paisley, told staff they would be transferred to other areas of the gallery or offered voluntary redundancies.
The job cuts represent about 8% of the gallery workforce, including some senior positions.
The job losses are part of the 63 full-time positions the 2016-17 federal budget, cut from cultural institutions over 12 months. The gallery was also hit by cuts, which took $36.8 million from "cultural and collecting entities within the arts portfolio".
The National Library was also expected to announce job losses in coming weeks, although the number was still being verified.
Community and Public Sector Union deputy secretary Beth Vincent-Pietsch said: "We are talking about highly qualified staff with a number of tertiary qualifications who had to work hard to get a job at the gallery. They are now feeling vulnerable and unsure of their futures."
Staff were told they will be considered for vacant positions without competition from other applicants, provided they "possess the ability to perform the tasks of the position within a reasonable period".
But Vincent-Pietsch said many gallery staff were specialists in their fields and might not be easily transferable.