Incumbent agency Influence Associates, which had held the account for the past two years and also worked for the firm before that, declined to re-pitch so as to focus on its core automotive business, said agency CEO Stuart Dyble.
Nelson Bostock has been tasked with shifting perceptions of Eddie Stobart from a traditional trucking business to one that is focused on people, technology and innovation.
The agency's remit includes corporate communications, executive media engagement and thought leadership activity.
Nelson Bostock deputy MD Will Hart said: "Eddie Stobart is transforming beyond trucking to meet new and growing market needs as the UK supply chain industry undergoes rapid evolution.
"We're looking forward to providing communications consultancy to CEO Alex Laffey and his executive team and helping them tell a compelling transformation story to business audiences."
The haulage company, famous for its twin-named trucks, was founded in 1970 and today boasts more than 2,200 vehicles operating throughout the UK and Europe. In 2010, Channel 5 launched a programme about the company - called Eddie Stobart: Trucks & Trailers - which is currently in its sixth series.
FTI Consulting continues to provide investor relations for Eddie Stobart.