Caroline Marland, the Guardian’s trailblazing former managing director who broke glass ceilings and helped others do the same, has died at the age of 80.

Marland, who became Fleet Street’s first female advertising director, was a pioneer in spotting the potential of the classified ad market for newspapers. She rose to the top of the male-dominated newspaper industry and championed other women throughout her career.

She spent 24 years at the Guardian, departing in 2000. Campaign magazine said her career was unusual in being both high-profile and “barely seasoned with controversy or feud”.

Marland, born in Dublin, was the eldest of three children. Her career in newspapers began in 1969, selling ads over the telephone for the Yorkshire Post – a relatively recent innovation at the time. After showing skill and charm, she found herself in demand on Fleet Street, accepting a job at the Times.

She found her long-term home when she moved to the Guardian in 1976, as a classified ad manager. She would go on to revolutionise the market and shift the Guardian’s reputation among advertisers.

Marland’s master stroke was to understand the potential of classifieds, which had been underpowered at the Guardian before her arrival. She later said a statistic from 1979 made her realise that the paper could do far better: 74% of Telegraph readers were too old for the jobs advertised.

She and the former Guardian editor Peter Preston oversaw a strategy producing new editorial sections with regular ad slots covering media, education and society. By the time Marland left the paper, the Guardian had attracted a major chunk of the UK’s recruitment ad market.

The fact she steered the Guardian’s commercial interests while being married to the Conservative MP Paul Marland, who died in 2021, was often the source of mirth. However, she said it was irrelevant, given she oversaw the paper’s commercial health.

It was her ability to nurture talent that many remember as her super power. Her deputy, Carolyn McCall, went on to become Guardian Media Group’s chief executive and now runs ITV. Sly Bailey, who went on to run Trinity Mirror, now Reach, also flourished under Marland.

McCall said: “Caroline started many people’s careers, including mine, through her position as the first female advertising director in Fleet Street and in the very people-centred way she led.

“There were always many women leaders at the Guardian who she encouraged and developed. She inspired great loyalty and created an amazing team, which I was always proud to be part of, and I have always thought of her with gratitude and affection.”

Katharine Viner, the Guardian’s editor-in-chief, said: “Caroline Marland was the managing director of the Guardian when I joined the organisation, and was a formidably impressive figure. She was a tough and clever businesswoman who got great results while also being famously kind and encouraging to the people around her, particularly women.

“She broke the glass ceiling over and over again, and became the first woman MD on Fleet Street; she also helped make it possible for me to be made the first woman editor-in-chief in 2015. And what glamour! We were lucky to have her.”

The former Guardian editor Alan Rusbridger said Marland was “a trailblazer in Fleet Street and a crucial figure in transforming the commercial fortunes of the Guardian”.

“She and her Conservative MP husband Paul may not have shared the Guardian’s politics, but she was devoted to making it thrive,” he said.

Marland’s daughter, Sarah Clothier, said her mother was “a powerhouse of energy”.

“Having Caroline as my mother was a unique experience – inspiring, challenging, colourful, exciting, and never dull,” she said. “She filled life with movement, opinions, laughter, and love, leaving an unforgettable mark on everyone who knew her.

“Long before breaking glass ceilings became a headline, my mother was doing exactly that, forging her path from telephone sales to become managing director of the Guardian. That took more than talent – it took her vision, nerve, resilience and her irrepressible charisma.

“Caroline was truly irreplaceable and will be sorely missed.”

Marland died after being involved in a car accident. She leaves behind three stepchildren, Alexander, Lara and Lucinda.