Ross beat celebrity blogger Perez Hilton and comedian Stephen Fry and US actor Ashton Kutcher to nab the first position.
Brand agency JCPR produced the 'Twitter index', which measured influence, instead of popularity, the Telegraph reported.
With the help of a specially developed algorithm, the agency tracked famous Twitter users around the world, ranking the top 200 based on the number of followers each user had, as well as the interest their posts generated among followers. This also included the number of times their name was mentioned and how many times they were 'retweeted' by others.
The global top 20 included Father Ted and The It Crowd writer Graham Lineham, who came in fifth, Downing Street at 12th, Jason Bradbury, host of Channel Five's Gadget show at 13th and Phillip Schofield, ITV's This Morning presenter, at 14th.
Jackie Cooper, founding partner of JCPR, said: "We are always trying to help our clients understand the influence that certain celebrities have over particular sections of society. Behind all the glitz and glamour that goes with fame, it's important to understand where real influence lies, which is often very different to mere popularity. The JCPR Twitter Index helps us define that within the hugely dynamic social media space."