The party won 28 seats, the minimum number that was needed to secure a majority.
The Liberal Democrats came second with 18 seats while UKIP, which previously had no seats, won three. Labour won three and Independents won two seats.
There is still one seat to declare at a by-election in Coker on 16 May, due to the death of one of the candidates there.
Alex Wood, who was suspended from UKIP after a photo of him apparently making a Nazi-style salute appeared on his Facebook page, failed to win a seat but came second.
Mr Wood, who said the photo actually showed him trying to grab a phone, received 665 votes in Blackmoor Vale. The Tory winner William Wallace had 1,410 votes.
Council leader John Osman said: "The people of Somerset have spoken.
"They've said they clearly understand some of the tough decisions which we had to make, but also they've seen the plan which we have for the future - the plan for jobs, the plan for investment, the plan for our vulnerable children.
"They've said 'yes' to that plan and I'm really, really happy they've said yes to it."
Conservative Mike Lewis, who won the Castle Cary seat, said: "The turnout in Castle Cary was 45% which was the highest in south Somerset.
"The turnout really does matter when it's a tight election. There's a lot of support for the Conservatives, particularly in rural areas."
The council was praised by North Somerset Conservative MP Dr Liam Fox for its "hard work". The party held on to control with the minimum of 28 seats needed for a majority.
Dr Fox said: "The Conservative result in Somerset was truly remarkable and a just reward for an excellent, hard-working council.
"The Conservative vote held up really well despite the rise in UKIP, with the real losers being the Liberal Democrats who came nowhere near their target of retaking the council."
Nigel Pearson, who won Chard North for UKIP, said "hard work" had won the party its seats.
He said: "We were out there every day on the doorstep talking to local people.
"This is just the start for UKIP - up until now we haven't been well organised."
The Liberal Democrat MP for Wells, Tessa Munt, said they had not had the number of gains they wanted but had "shown we can hold our own in the face of pretty interesting onslaughts from different groups".
She said: "You have to say UKIP is here with a vengeance. It's clearly a political force that can measure itself against the best of us across Somerset."
Boundaries have changed since the last election in 2009 and the total number of seats on the council has decreased from 58 to 55.
The Conservatives have retained overall control of Somerset County Council.