The British designer will replace Estrella Archs at the French fashion house, with his debut collection being presented during Paris Fashion Week in October, and he is confident about his new role.
He said: "Yes, I'm totally aware and respectful of the pressure but at the same time, I've run my own business for eight years and worked in lots of places.
"I think as soon as you start worrying and thinking about that too much, you're not concentrating on doing good work, which is the most important thing."
Deacon - who is likely to stay away from the catwalk for the first two seasons - will continue to produce his own line and wants to bring his own touch to Ungaro.
He told WWD: "I obviously don't want to infringe upon my own line, but I like things that are very feminine, lots of colour, great prints, great quality, some unusual cuts. All of those things that I like in the world of fashion design I'm going to bring to what I feel is appropriate for the Ungaro woman."
Last month, Ungaro's chief designer Estrella Archs quit Ungaro, citing "irreconcilable differences".
Estrella's departure came hot on the heels of Lindsay Lohan parting ways with the company after she was brought in as artistic adviser.
Her debut collection was critically panned and she wasn't involved in the range which was showcased at Paris Fashion Week earlier this year.