Wieck joins Synovate from Kraft, where she was marketing manager for its chocolates and biscuits business in Romania.
Her career includes marketing and sales positions first with P&G in Bucharest and then Coca-Cola in Romania and Croatia.
Following this, she joined Ansell Healthcare in Brussels as marketing manager for emerging markets before returning to Romania in a senior marketing management position with Starfoods - PepsiCo.
Kurt Thompson, Synovate chief executive for Central/Eastern Europe and the Middle East, said: "We look to Carmen to maintain our leading position in the Romanian market, using the skills and expertise she has gained by working with some of the world's best-known brands."
Wieck said: "I feel very positive about our future, having collaborated with Synovate in different countries for more than 10 years.
"I am confident that Synovate's leading-edge solutions and access to expertise from across our global network, combined with an even stronger understanding of client needs, will make the difference in maintaining our leadership position in this market."
Separately, Synovate was awarded the Market Research Society David Winton award for innovation and methodology this week in London.
The award was presented to Synovate for its paper - 'A new measure of brand attitudinal equity based on the Zipf Distribution.'
Published in the International Journal of Marketing Research, the paper describes a new measure of attitudinal brand strength for use as a dependent variable in survey questionnaires.
It was written by Jan Hofmeyr, Victoria Goodall, Martin Bongers and Paul Holtzman.