Mr Cartlidge replaces the outgoing Tim Yeo who was deselected in February last year by South Suffolk Conservative Association members.
Mr Cartlidge secured 27,549 votes to win ahead of Labour’s Jane Basham who secured 10,001 votes.
After the vote was announced Mr Cartlidge thanked his team for their support and vowed to work hard for his constituents.
He said: “We’ve been all over this constituency and that’s how we will continue as an association and how I want to continue as a member of parliament representing the whole of South Suffolk.”
Mr Cartlidge thanked his wife Emily. In the past year he has celebrated the birth of twins and said had someone told him he would be voted in as an MP in the same year as having twins he would have probably fainted.
“It’s been hard work but I’ve been incredibly honoured to have been elected as MP for South Suffolk.
“It’s an incredible constituency, with lots of challenges and issues that have been raised throughout the campaign.
“My promise is I will repay you by working as hard as I can to be your principle public servant representing nothing but the best interests of the people of South Suffolk.
It was a disappointing night for Liberal Democrat candidate Grace Weaver, whose party came second in 2011, dropping to fourth with 4,044 votes.
In total 51,727 votes were cast in the region, 70.1 per cent of eligible voters.
Overall votes:
*Conservatives - James Cartlidge 27,546
Labour - Jane Basham 10,001
UKIP - Steven Whalley 7,897
Liberal Democrats - Grace Weaver 4,044
Green Party - 2,253
Published by Suffolk Free Press.