The 13-episode run is set in 1962, with John F Kennedy in power and the agency needing to work out how to connect with the emerging youth market.
As a result, Draper is chivvied into recruiting two young creatives in the first episode, which also sees him take his wife on a disastrous Valentine's Day dinner to the Savoy Hotel.
Other returning lead characters include Pete Campbell, the creative who tried to blackmail Draper into giving him the head of account services job last series, and Peggy Olsen, the first woman to become a copywriter at Sterling Cooper.
'Mad Men' won the 2008 Emmy for outstanding drama series and the Golden Globe for best television series, drama, in 2008 and 2009.
The buzz around the return of 'Mad Men' has been widespread featuring on the front of the Guardian Guide on Saturday. The piece highlighted the Twitter buzz around Don Draper and company. Don Draper, along with many other fans of the show are tweeting away merrily with at least five Peggy Olsens going strong.
The tweeting is the work of fans who were last year given the greenlight by US cable channel AMC, which produces 'Mad Men' in the states.
The Times today has a feature focusing on the real mad women of Madison Avenue with interviews with Mary Wells Lawrence and Charlotte Beers.
The Independent has a piece, Mad Men: A true guilty pleasure declaring that "Mad Men...is smart, subtle, quietly engrossing and totally original television, and the chattering classes are right to be chattering about it."
The BBC has a piece on the look of 'Mad Men' looking at the sharp suits and extraordinary outfits worn by the show's women.