Dunedin-born Mark Jennings was educated at Otago Boys' High School. After realising he wasn't going to be an accountant, Jennings abandoned Otago commerce studies for a journalism course at Wellington Polytechnic. In 1977 he joined TV One as a trainee journalist in Christchurch, before moving to the Wellington newsroom. Jennings was mentored by TV One news head Doug Eckhoff and Christchurch bureau chief John Knowles, who "took me under his wing and taught me television."

In 1979 Jennings crossed the ditch and spent a decade working in Australian current affairs, on TV news mainstays like ABC NewsNationwide, 7.30 Report, and 7 News

Jennings returned home from Melbourne in 1989, to set up the Christchurch news bureau of upstart new channel TV3. He had spurned an offer to work on TVNZ's Holmes show so he could run the rival network's South Island news operation, and file stories for 3 News, Nightline and 60 Minutes. 

In a 2007 Listener interview with Matt Nippert, Jennings described the Christchurch team. "It was a group of people that were thrown together and by sheer luck we had complementary skills and all got on. No matter how bad the company situation was, we refused to think about it and just ploughed on: our sole focus was beating TV1. We wanted to do it on a daily basis, and we did." 

In January 1995 Jennings was made TV3's Head of News and Current Affairs. From the start the channel was the underdog, wrestling for ratings and credibility against the incumbent state-funded TVNZ. There were also periods of uncertainty over the channel's future.

During his two decade-plus tenure Jennings achieved several ratings wins in key demographics, and saw off at least six news bosses at TVNZ, sometimes collegially. In 2007 he praised ex-TVNZ news chief (and one time TV3 reporter) Bill Ralston, noting that “on expensive overseas jobs it makes sense to co-operate at times, and we never sweated the small stuff.” 

Jennings also outlasted several executives at TV3. As he told Nippert: "That’s because nobody understood news enough to get rid of me. And I do see myself as an institutional memory. When the management team are sitting at the table, someone will say, 'Why don’t we try this?' And I’ll say, 'No, we tried that 10 years ago, and it didn’t work then. And we tried that five years ago and it didn’t work then.' Everybody thinks I’m very conservative, but I don’t think I am. We’ve done lots of high-risk things at times."

Jennings managed several high profile staffing shifts. In 1998 John Hawkesby was replaced as nightly newsreader by Carol Hirschfeld and John Campbell. Neither of them had read the news previously, but Jennings was keen to have journalists fronting the news, a trend that would typify appointments during his  tenure. In 2000 he headhunted reporter Mike McRoberts from TVNZ. The two endeavoured "to change the way NZ TV covers foreign conflicts", with McRoberts flying in to provide a local take on a number of big international stories. When Campbell and Hirshfield departed to host Campbell Live in 2005, Jennings paired McRoberts with Hillary Barry, as primetime news anchors. 

At the the other end of the daily schedule, Jennings recalls struggles "trying to get our early morning news programmes to succeed". But he departed from TV3 with Paul Henry going "great guns ... I owe him a lot". On resigning in 2016, Jennings made special mention of two longtime colleagues: Melanie Reid ("a brilliant and natural journalist") and 3 News 6pm producer Mike Brockie ("the best news producer I've come across").  

Jennings rated the two biggest stories of his career to date as the Pike River Disaster and the second Christchurch Earthquake, with their challenges of "deciding on the extent of resourcing and live coverage." At times 3 News' coverage made the headlines, for example 'Corngate' and a public relations meltdown during Kim Dotcom’s Internet Mana Launch.

Throughout, Jennings' reputation has been as a calm and considered steward. Jennings' 2007 Listener interview is preceded with a note that, "Jennings took a full 24 seconds to mentally compose his response to our first question."

Over three decades current affairs has seen enormous changes in how news is gathered and shared: from the nightly TV news campfire and newspaper sub-editors when Jennings started out, to the brave new world of 24-hour digital and clickbait. In 2014 he was asked to lead the task of establishing a combined newsroom for the MediaWorks empire, serving television, radio and digital. The new operation was christened NewsHub, and the 3 News brand dropped, along with shows Campbell Live and 3D

Jennings has mentored generations of reporters in TV3 newsrooms, and via training institutions. After his resignation was announced to staff on 24 February 2016, a flood of tributes poured in on social media from colleagues — including some of those he'd made redundant.

Rachel Smalley called Jennings "a brilliant news brain, the finest of managers and one of my all-time favourite people." Vernon Small described him as a "beacon of competence and good judgement". Melanie Reid, who first worked with Jennings in 1989, recalled that "he mentored me for years, and I have seen him take many a journalist and do the same. He knew our strengths and helped us with our weaknesses". Reid argued Jennings' own strengths as a journalist helped make him a great boss. "His judgement on stories is impeccable, tough, fair, always decent." Media commentator Russell Brown called him "the best and most influential news manager of his generation".

In an extended piece for The Spinoff, David Farrier recalled how Jennings had remained the "one constant factor" during many changes at TV3. "He cared about news, because he cared about people. Because he understood that news was all about people: whether it was the people in the stories, or the people making them. Yes, he knew it was a numbers game, but this was secondary to the humans involved." 


Sources include
Mark Jennings
Melanie Reid
David Farrier, '"He stood up for news" – David Farrier salutes departing 3 News head Mark Jennings', The Spinoff website. Loaded 24 February 2016. Accessed 25 February 2016
Matt Nippert, 'Mark Jennings: News man' (Interview) - The Listener, 24 February 2007
Colin Peacock, 'Long-serving news chief Mark Jennings resigns from Mediaworks', Mediawatch, Radio New Zealand, 25 February 2016
Unknown Writer, 'Online news boss to replace Jennings at MediaWorks- The NZ Herald, 25 February 2016
Unknown Writer, 'Head of news resigns from Mediaworks' Radio New Zealand website. Loaded 24 February 2016. Accessed 25 February 2016
'Mediaworks Management' Mediaworks website. Accessed 25 February 2016