Jane Fonda has a simple message for Hollywood’s heavyweights: Older women are the fastest-growing demographic in the world, so start making more movies and TV shows about them.

The two-time Oscar winner is starring alongside Diane Keaton, Candice Bergen and Mary Steenburgen in Book Club, a movie about four long-time friends in their 60s who rev up their love lives after reading the erotic thriller Fifty Shades of Grey.

The film enjoyed box office success in the US, and Fonda says more movies that portray older women as robust and lively are needed.

“What’s important is that the narrative of older women is part of the stew, that we are not left out,” she said on Monday while in Sydney to promote the film.

“Older women are the fastest-growing demographic in the world and to rob audiences of our points of view and our realities and make us one dimensional is bad for everybody, including us and men as well, because we have a lot to bring to the table.”

Jane Fonda and director/producer Susan Lacy talk shop in Beverly Hills in July. Photo: Getty

The actor is also in Australia to star in her conversation-style stage show, An Evening with Jane Fonda, in Sydney and Melbourne this week.

At 80, the actor is busier than ever making movies and Grace and Frankie, the hit Netflix comedy about two friends (Fonda and Lily Tomlin) who unexpectedly end up living together after their husbands fall in love and marry each other.

The show has won fans not only among older women, but younger audiences.

Lily Tomlin and Fonda have been a success in Grace and Frankie. Photo: Getty

“One of the reasons that younger people are liking Grace and Frankie so much is because they think, ‘Oh grandma could still be getting it on, and they’re still having a good time’,” Fonda said.

Another project Fonda has in the works is a sequel to her hit 1980 comedy 9 to 5, which also starred Dolly Parton and Tomlin in a story about three women who took on their sexist boss.

Despite nearly four decades having passed since 9 To 5 hit the big screen, Fonda says sexual harassment and unequal pay are still big issues in the workplace.

“We want to deal with the new reality of today’s offices that are now digital, and often part of the gig economy, and also sexual harassment is still unfortunately going on in offices,” she said.

In terms of her own workplace in Hollywood, Fonda says things are beginning to change following the Harvey Weinstein scandal.

“I think that everyone is much more aware of what constitutes bad behaviour,” she said.

“I think a lot of guys didn’t really understand how their behaviour was viewed as inappropriate by women and demeaned women and showed a lack of respect.

“I think there’s much more awareness of that. People are being more careful.”

-AAP