Dismissing Chancellor George Osborne's claim the Budget would help "makers, do-ers and savers" across the whole of the UK, Mr Swinney said: "Independence is the only way Scotland can properly create opportunity and secure the investment in public services and the economy Scotland needs.
"Once again Westminster has failed to deliver for Scotland."
"Scotland is a wealthy country and we can more than afford to be independent."
He hit out at Mr Osborne's plan to force a Commons vote on extending spending cuts beyond the 2015 Westminster election and into the next parliament.
He said: "This budget confirms that remaining with Westminster will mean more austerity with £37billion worth of cuts still to come over this Parliament and tens of billions to come afterwards.
"In addition Scotland's budget could be subjected to additional cuts if Scotland doesn't vote for independence and Westminster takes the knife to the Barnett formula.
"It is only with independence that Scotland will be able to make the decisions on tax and spending that Scotland needs."
Mr Osborne used his fifth Budget to freeze duty on Scotch whisky, boosting an industry which employs 10,000 people in Scotland and 35,000 across the UK.
The oil industry was promised new tax allowances to encourage investment in the North Sea.
However, Mr Osborne used his speech to highlight a recent £3billion downgrading of oil revenue forecasts from the independent Office for Budget Responsibility.
He said: "The Scottish economy is doing well and jobs are being created.
"But this is a reminder of how precarious the budget of an independent Scotland would be. Britain is better together."
The Scotland Office said Scottish manufacturers would benefit from UK-wide measures to cut fuel bills for firms. Scots companies can expect to save £500million by 2018/19, officials said.
Companies investing in enterprise zones in Irvine, Nigg and Dundee will also benefit as tax breaks were extended for three years up to 2020.
On the personal tax allowances, 25,000 low earners will be taken out of tax altogether by raising the threshhold to £10,500. A further 2.2million earners will be £62 better off, on average.
In a boost for students, Mr Osborne pledged support for a scheme supporting study trips to the US set up in the wake of the Lockerbie bombing. The Lockerbie-Syracuse Trust will receive £100,000.
Mr Osborne announced the measure after visiting Lockerbie with Dumfriesshire MP and Scotland Office Minister David Mundell. The Chancellor also praised another Scots MP, Alan Reid, the Lib Dem who represents Argyll and Bute. He said VAT on fuel for air ambulances and inshore rescue boats would be scrapped following a campaign involving Mr Reid.
Scottish Conservative leader Ruth Davidson claimed credit for freezing the duty on Scotch.
She said: "This tax boost will not only benefit the big players, but also the small independent distilleries right across Scotland who rely on our domestic market for sales.
"I don't believe any product should be taxed at 80% and if the Chancellor hadn't acted, that's what we would have seen for a bottle of Scotch.
"Taking this action shows the government is prepared to take on board legitimate concerns from across the UK."
She added: "I put the case repeatedly to the Chancellor. The Chancellor responded."