Lucas Heights is a suburb in Sydney, Australia. It is adjacent to Menai and Engadine.

It is most notable for being the site of the ANSTO research establishment originally established by the AAEC and home to the HIFAR research reactor. HIFAR is soon to be replaced by a more modern reactor, OPAL. The decision to build OPAL and its siting have both been the subject of criticism from some resident and anti-nuclear groups.

Lucas Heights is also close to a non-nuclear waste management facility, which was for many years a major disposal site for sanitary carters. Some of the full landfills on this site are presently being sequentially redeveloped into a sporting complex containing playing fields for soccer, netball, rugby league and a golf driving range.