The 23-year-old has scored 13 goals in 27 appearances this term to help guide Arsene Wenger’s side to the top of the table.
Ramsey has not featured for Arsenal since Boxing Day due to a thigh injury but Vieira says the Wales international has had a major influence in his side’s campaign so far.
|7/2||Arsenal are 7/2 with bet365 to win the Premier League|
“At the start of the season he was fantastic because of the number of goals he scored from midfield but also the number of goals he created.
"If Arsenal are top it's because he has been the best player as the start of the season.”
Vieira praised Wenger for maintaining his trust in Ramsey, whose early career at Arsenal was disrupted after he suffered a double leg break in February 2010.
"Arsene is really good at developing and trusting young players,” Vieira continued.
“What's stopped Ramsey's progress was injuries in the last few years but now he has sorted that out.
"Credit to Arsenal and Arsene who believed in him.
"And credit to Aaron as well because even with all the injuries, he's kept working hard, believing in himself and that he could make it.
"The ability has always been there and I'm pleased he is now showing what he is capable of."