The £10m improvements form part of nearly £30m investment in Olympia by the venue’s parent company, Capital & Counties Properties (Capco).
The investment also saw Olympia's West Hall reopen in December 2011 as a 9,000sqm, two-storey exhibition facility following a £20m project.
The most recent work – completed this month - aimed to improve facilities in the conference centre on the third floor by adding retractable walls to the East Hall.
The new walls mean the space can be divided into three separate rooms, for 250, 170 and 80 delegates theatre-style.
In addition, work has included a revamp of Olympia Two's Level One and infilling the atrium on Level Two.
The existing escalators and stairs between these floors have been removed to produce more effective exhibition space, while the ground floor was reconfigured to create a large traffic marshalling area.
EC&O Venues managing director Nigel Nathan said: "These projects are further positive steps in helping Olympia sustain its position as a world-class venue. The upgrades to Olympia Two demonstrate that our business is adapting to the changing demands of the industry."