The prizegiving, which fetes the best of the city's theatre scene, included wins for Blanchett and Weaving for their roles in the Sydney Theatre Company's touring production of Anton Chekhov's Uncle Vanya.
The Elizabeth star took home the Outstanding Lead Actress award in the international category, while Weaving was named Outstanding Supporting Performer.
The night was also a big one for Spacey as he was honoured with the Helen Hayes Tribute for his contribution to the arts both as an actor and as a theatre ambassador.
The American Beauty star, who is artistic director of the Old Vic theatre in London, follows in the footsteps of past recipients, including Derek Jacobi, James Earl Jones, Angela Lansbury, Stephen Sondheim and Lynn Redgrave.
Speaking before the ceremony, Spacey told the Washington Post the awards should serve as a reminder for U.S. officials to protect funding for the arts: "Washington has always had vibrant theatre. I've been a part of it for many, many years. I've done six plays here. So for me, tonight is particularly valuable and important.
"We (need) to be putting much more money into the arts than we are. It's hugely important to our culture, it's important to us as a nation, and I think any nation that doesn't embrace its arts and stand up for its arts is a lesser country."
Miss Potter is a biopic about Beatrix Potter (Renee Zellweger)—the literary phenomenon of the early 20th century who created the hugely popular Peter Rabbit books. The film examines how she rose to fame in Victorian England a time when women were only expected to marry and run a home. As the story begins Beatrix 32 is well-adjusted despite being unmarried and living with her well-to-do parents. An accomplished painter she dreams of publishing her pet animal drawings as well as the stories that go with them and in neat small-sized books perfect for children. Of course most publishers scoff but one decides to publish Beatrix’s “bunny book ” as a lark and soon sets in motion a publishing juggernaut. During the process Beatrix also falls in love with her young editor Norman Warne (Ewan McGregor) and agrees to marry him much to her mother’s chagrin (he’s a “tradesman ” after all). Basically Miss Potter ends up living the life she wants to lead bucking whatever rigid system put before her. Zellweger is playing yet another English rose but this time without the extra weight. Although not nearly as endearing and quirky as Bridget Jones Zellweger’s Beatrix is still plucky and outspoken willing to stand by her beliefs and forge ahead despite the opposition she faces. In other words Zellweger—who won her Oscar playing a similar part in Cold Mountain—could do this in her sleep. McGregor too seems comfortably fitted for the role of Norman an earnest fellow with good moral fiber a determination to succeed and love in his heart for Miss Potter. Veteran British character actors Barbara Flynn (HBO’s Elizabeth I) and Bill Paterson (Bright Young Things) effectively play Beatrix’s parents with Dad Potter being the more sympathetic and Mom Potter being the uptight battleaxe. And finally Emily Watson who does a nice turn as Norman’s spinster sister Millie. A brash intelligent woman who also speaks her mind Millie thoroughly enjoys life as an unmarried woman and quickly takes Beatrix under her wing. Director Chris Noonan waited a decade after helming the Oscar-nominated Babe before finding his follow-up project setting his sights on Miss Potter. There’s definitely some symmetry to his choice with both beautifully framed films having much of the same sweet-natured sensibilities as well as er animals. Much like Finding Neverland which showed how James Barrie came up with Peter Pan Miss Potter works best when Beatrix is standing up for her rights falling in love and drawing her adorable illustrations her “friends ” as she calls them who come to life and talk to her. Thankfully Noonan and screenwriter Richard Maltby don’t have the animated characters actually speak—only Miss Potter can hear them--but its still a clever device and definitely brings up feelings of hearth and home remembering those stories all over again. Unfortunately the film stalls a bit towards the end when the scenery shifts to England’s the Lake District where the real Beatrix Potter eventually retired to and helped preserve for future generations. Still overall Miss Potter is a charming look at one of the literary world’s more successful authors who was also a feminist and an environmentalist. Pretty amazing lady actually.