The contract, which was awarded on a one-year rolling basis, is for 16 weekly and fortnightly titles and a number of ad hoc products.
Egmont UK production manager Sarah Colley said: "Southernprint's consistent print quality, excellent time-keeping and supportive customer services team all played a part in our decision to renew our magazine printing contract."
All 16 titles are printed at Southernprint's web offset facility in Poole. Files are uploaded and approved by Egmont UK's editorial and production teams using a Prinergy workflow.
Lee Godwin, Southernprint sales director, said: "The Southernprint team has developed a really strong relationship with Egmont, producing consistently high-quality products week-after-week. The renewal of the contract is testament to this."
Egmont UK, which is part of the Scandinavia-based Egmont Group, produces around 12m magazines a year, including Dora the Explorer, Ben 10, Thomas & Friends, Barbie, Go Girl and Toxic.