The competition, which took place at The O2 from 13-20 November, saw the caterer provide food for over 6,000 hospitality guests, plus players and family.
Jeremy Wood, chairman of Mecco, said: "We love the fast pace of the Barclays ATP World Tour Finals and being in such a landmark venue adds to the excitement.
"Working with the ATP is an utter pleasure as they have very much innovated the tennis scene. We too thrive on change and we bounce off their constant ingenuity, as it means that we can also develop and excite through the guest and player entertaining."
The caterer designed seasonal menus to meet players' exacting dietary requirements, as well menus for the various hospitality areas.
The menus reflected the autumn harvest with dishes including wild sea bass with shellfish velouté and crispy spinach and roasted squash arancini with hazelnut pesto.
Mecco has a number of sporting contracts including The Aegon Championships, The Ryder Cup and The British Grand Prix at Silverstone.