Matt Prosser, of South Oxfordshire District Council, was announced as the new council chief for both authorities at a full council meeting of Weymouth and Portland Borough Council tonight.
Council leader Mike Goodman told members of Mr Prosser's appointment after councillors agreed on a budget that will see a rise in council tax of 1.99 per cent.
Cllr Goodman said: "He's young, energetic and enthusiastic.
"He impressed throughout the interview process. I have no hesitation in recommending him for the appointment."
Current chief executive David Clarke is retiring at the end of April.
Mr Prosser's salary will match Mr Clarke's - £110,00 plus a performance related bonus of £5,000.
All councillors voted for the appointment of Mr Prosser.
The approved budget will see the authority save £900,000 over the coming financial year.
Extra council income will be generated in 2014/15 by increasing fees at Weymouth Crematorium and savings will be made by running fewer festivals and events.
Councillor Peter Chapman, the council's finance spokesman, praised council staff who, he said, have faced the 'unpleasant situation' of not knowing if their job is secure amidst a public sector spending squeeze.
He told councillors: "We should be really proud of where we are as a council and what we have achieved.
"We have been doing a huge amount of work in the partnership.
"We are going to be innovative, bold and not precious about some of the things we thought were important in the past."
Councillors voted in favour of an amendment from the Labour group to the 2014-15 budget, which was to take £150,000 out of council reserves for investment purposes.
Councillor Mike Byatt said: "This amendment is intended to make sure we have a strategy for taking this council forward.
"It's about doing something positive for the future of this area."
Councillor Andy Blackwood described the budget as 'a damage limitation budget' and said the poor have been hit hardest.
He said: "I think we have cut services. I think services are in danger and I think people will be affected.
"We've pushed people towards food banks - there's no getting around that."
Some 31 members of the council voted for the budget whilst Councillor Rachel Rogers abstained from voting.