Mullin, who joins this week, will lead the charity’s brand, insight, marketing, communications, external affairs and commercial activities. As part of the executive team she will play a key role in delivering the trust’s Going Local strategy.
Launched in 2010, this strategy aims to engage the public, raise membership, increase the trust’s relevance to the whole nation, and empower properties.
Fiona Reynolds, director general of the National Trust, said: 'This is a pivotal new role for the trust and Clare will be responsible for developing and implementing an integrated marketing, communications and external influence strategy, helping us in our ambitious plans to reach and deliver benefit to the whole nation.
'Clare brings a wealth of experience and knowledge to the trust, having been part of the senior leadership team that transformed Dyson into a brand synonymous with innovation and cutting-edge technology.
'Her wide consumer and marketing experience will be of immense value to the trust.'