The flamboyant Mr Gyngell, who famously turned around the ailing TV-am only to see the company lose its franchise to GMTV (then Sunrise) in the last round of ITV awards, will also become chief executive of subsidiary Yorkshire Television, one of the country's leading production companies.
He will replace John Fairley, who left last month, apparently after being told he would not get the top job at YTT.
Ward Thomas, YTT chairman, said that the appointment would give the company an advantage in international markets as well as in the UK.
"Bruce is experienced in every facet of our industry," Mr Ward said.
Mr Gyngell, 65, has spent the past three years as executive chairman of Kerry Packer's Nine Network in his native Australia, where he took the network to number one position in terms of audience share.
Mr Gyngell began his television career in Australia as a presenter, and was managing director of both Nine Network Australia and Seven Network.
He became managing director of TV-am in 1984. When the company was closed in 1992, by which time Mr Gyngell had been made chairman, it was one of the most profitable franchises in Britain.
During his TV-am tenure, he also gained a reputation as a mystic - a believer in mantras and massages - and a man with odd tastes in clothes, cajoling his staff to wear pink to promote good fortune. In accepting the YTT job, Mr Gyngell, dubbed the Pink Panther, inherits a company that has only recently returned to the black following overselling of airtime that obliged YTT to repay advertisers over the course of 1993.
The company lost £7.9m that year, compared with a pretax profit of £16.7m in 1992. Last year, the company managed profits of £10.5m for a 15-month period, reflecting the changed year-end.
YTT has also been saddled with the effects of overbidding for its franchises in 1992.
Mr Gyngell may also face the prospect of a takeover bid, media analysts said. YTT shares have risen sharply in recent days, reaching the 500p by late last week, compared with 450p earlier in the month. The shares closed yesterday at 489p.
Some of the rise was fuelled by expectations that television and leisure group Granada was eyeing YTT, ready to move once media cross-ownership rules were relaxed.Industry insiders believe at least one group of companies is looking at a bid.