"He possesses a quality that I value in all my advisers: a willingness to tell leaders what we need to know even if it's not what we want to hear."
Clapper told Obama he was "humbled, honoured and daunted" by the nomination, and pledged to earn the support of politicians and the public.
If confirmed by the senate, Clapper will replace Blair, who resigned last month amid mounting domestic security concerns following a failed car bomb attempt in New York's Times Square on May 1 and the botched attempt to blow up a US airliner on Christmas Day.
Obama said he wants senators to act quickly to confirm Clapper, saying the nomination "can't fall victim to Washington politics".
"The job is often described as a bureaucratic nightmare," said our correspondent.
Politicians from both parties have voiced objections to Clapper, saying he has been combative and sometimes obstructive under questioning on Capitol Hill.
Those critics also question whether he will have any sway in Obama's influential intelligence inner circle, which includes John Brennan, the White House counterterrorism adviser, and Leon Panetta, the director of the CIA.
Kit Bond, the Republican vice-chairman of the Senate Intelligence Committee, said he would not back Clapper because "he lacks the necessary clout with the president, has proven to be less than forthcoming with congress, and has recently blocked our efforts to empower the director of national intelligence [DNI]".
Pete Hoekstra, another Republican who is the House Intelligence Committee's ranking minority member, said Clapper "does not have the clout or independence to be the voice that provides an alternative to the Obama administration's prosecute after-the-fact approach to terror".
Al Jazeera's Nick Spicer, reporting from Washington, said Clapper previously worked under Donald Rumsfeld, the former secretary of defence, with whom he clashed with.
Clapper is currently an important aide to Robert Gates, the current US defence secretary, and one defence official said he enjoys strong backing from Gates.
While working under Gates, Clapper, "dismantled some of the more controversial policies of Donald Rumsfeld, such as the military monitoring anti-war activists operating out of churches and schools," our correspondent said.
The DNI oversees the 16 agencies that make up the US intelligence community, including the Central Intelligence Agency and the National Security Agency (NSA).
Clapper is currently undersecretary of defence for intelligence, the highest intelligence post at the Pentagon, as well as the director of defence intelligence, which reports directly to the DNI.
He retired from the air force in 1995 after a 32-year career, and spent many of the ensuing years working for private defence contractors and teaching.
Clapper has also held crucial intelligence posts, including from 2001 to 2006 as the first civilian head of the National Geospatial-Intelligence Agency, which collects and analyses data from commercial and government satellites or aircraft.
If confirmed, he would become the fourth director of national intelligence since the cabinet-level position's creation in 2004.
The post was created by George Bush, the former US president, in a reorganisation of the intelligence bureaucracy to fill shortcomings in inter-agency collaboration exposed by the September 11, 2001, attacks.