Diane (Di) Beamer (born 15 July 1960) is a former Australian politician. She was a member of the New South Wales Legislative Assembly between 1995–2011 representing the electorates of Badgerys Creek (1995–1999) and Mulgoa (1999–2011) for the Australian Labor Party.
Beamer joined Labor in 1975. She graduated from Sydney University with a Bachelor of Arts (BA). She is married to Sydney journalist David Humphries and has 6 children (Lauren Calliope, Alex, Julia, Michael, Georgia, Madeleine, and newly adopted favourite daughter, Jemma, from a previous marriage to Senator Steve Hutchins.
Beamer is a member of the Board of Ripples Aquatic Centre and a Parliamentary Patron of the Spokeswomen Program.
Beamer was elected a Councillor of Penrith City Council 1989-95, was Deputy Mayor from 1992 to 1993 and Mayor from 1993 to 1994.
Beamer ran unsuccessfully for the seat of Badgerys Creek in 1991, but was elected to it in 1995. Following Badgerys Creek's abolition, she was elected as Member for Mulgoa in 1999, which she held until 2011. In April 2003, she became Minister Assisting the Minister for Infrastructure and Planning (Planning Administration), Minister for Juvenile Justice and Minister for Western Sydney.
She was an electoral officer for the Hon. John Brown, whilst he was Minister for Sport and Tourism from 1985 to 1989.
In 2003, an officer of Liverpool City Council approved a development application for a shopping centre at Orange Grove, in Warwick Farm, just north of central Liverpool, consisting primarily of factory outlets in an area zoned under its Local Environment Plan (LEP) for industrial uses, in which retailing was generally forbidden, except for a limited range of "bulky goods" or goods produced on the premises. The Westfield Group successfully overturned the approval in court, as being contrary to the Council's LEP, and the court ordered the closure of the centre's retail activities in January 2004, with a deadline ultimately extended to 30 June 2004.