According to brand agency JCPR's 'Twitter index', Ross' authority also rates higher than Stephen Fry and Ashton Kutcher -- who recently won the race to add one million followers.
The results were based on a unique algorithm, rating the number of followers each user has as well as the interest their posts generate among followers, including the number of times their name is mentioned and how many times they are 'retweeted' by others.
Ross tops the list, followed by celebrity blogger Perez Hilton, with Stephen Fry rounding out third.
Kutcher or @AplusK as he is known on Twitter now has 1,624,474 followers and ranks 4th behind @PerezHilton who has 754,647 and @StephenFry who has 476,033. As @Wossy, Ross as 242,737 followers.
JCPR found six UK Twitterers in the global top 20, including Graham Linehan at 5th, Downing Street at 12th, Jason Bradbury, host of Channel Five's Gadget show, at 13th and Philip Schofield at 14th.
Jackie Cooper, founding partner at JCPR, said there is serious value in researching Twitter influence.
Cooper said: "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."
JCPR's index will make interesting reading to US actor Kutcher, who placed 4th, and recently went head to head with CNN (7th) to be the first Twitterer with one million followers.
He even took out billboard advertising to achieve the goal.
Ashton and his wife, Demi Moore (ranked 6th), were in large part responsible for making 'Britain's Got Talent' star Susan Boyle famous in the US.
It was only when Demi confessed that Boyle had moved her to tears after seeing her on Ashton's twitter page, that mainstream media and YouTube views exploded.
The Top 20 Influential Twitters, according to JCPR:
- Jonathan Ross (@Wossy)
- Perez Hilton (@PerezHilton)
- Stephen Fry (@StephenFry)
- Ashton Kutcher (@AplusK)
- Graham Linehan (@Glinner)
- Demi Moore (@MrsKutcher)
- CNN (@CNNbrk)
- Lance Armstrong (@LanceArmstrong)
- New York Times (@NYTimes)
- Wil Wheaton (@Wilw)
- Shaquille O'Neal (@The_Real_Shaq)
- Downing Street (@DowningStreet)
- Jason Bradbury (@JasonBradbury)
- Philip Schofield (@Schofe)
- Soulja Boy (@SouljaBoyTellEm)
- Jimmy Fallon (@JimmyFallon)
- Barack Obama (@BarackObama)
- John Mayer (@JohnCMayer)
- Michael Arrington (@TechCrunch)
- Ryan Seacrest (@RyanSeacrest)