Mark Bruton-Young, 36, was accused of killing six-month-old Harriet by smothering her at the end of June last year.
After a two-week trial at Bristol Crown Court, a jury of eight men and four women took 18 and a half hours to acquit Mr Bruton-Young, an architect, of a single charge of murder.
After leaving the dock, Mr Bruton-Young embraced his wife, Clare, 36, who has supported him throughout the trial.
He raised the alarm after he found Harriet dead in her cot. A post-mortem examination failed to establish the cause of death.
Prosecutors had claimed Mr Bruton-Young of probably smothering Harriet 'gently' with a pillow as she slept.
'We say he killed Harriet deliberately because he could not face up to life as a father.
'It is proud and fulfilling to most men but it was a burden to this man. A burden he could not cope with,' prosecutor Paul Dunkels QC told jurors.
'It depressed him and drove him to take the life of his baby in a way his sophisticated searches on the internet led him to believe would go undetected.'
Jurors were told that Harriet was an unplanned child when she was born in December 2008. Work colleagues had described Mr Bruton-Young as 'depressed'. The court heard Mr Bruton-Young had received counselling and was seeing a health visitor in the six months after Harriet's birth.
The prosecution said that information gathered from Mr Bruton-Young's work computer showed that he initially searched for advice on bonding, depression and fatherhood.
In the weeks leading up to his daughter's death, Mr Bruton-Young was alleged to have begun to search for terms such as "signs of deliberate suffocation" and "how quickly can a baby suffocate?".
He told jurors he was concerned that he would accidentally hurt Harriet, but stressed: "I would never harm her deliberately."
He said he had contemplated having Harriet adopted, "to give her a better life", but insisted he loved her.
Describing how he found Harriet on the morning of her death, he told jurors: "I went to check on her and found her lying face down in her cot.
"She looked cold and white. I touched her and I couldn't believe it.
"I went to get Clare and she came into the nursery and picked Harriet up. I made a 999 call and Clare started screaming. Afterwards I felt confused.
"I had been a poor father but now all I wanted was another chance. I just wanted my daughter back but I couldn't have her back."
A spokesman for Gloucestershire Police said after the verdict: "The police treat all sudden and unexpected deaths in infants very seriously and work closely with other agencies and key professionals in order to thoroughly investigate each case.
"The evidence that was gathered in this case was carefully examined and referred to the Crown Prosecution Service, who subsequently decided that Mark Bruton-Young should be charged and the evidence brought in front of a jury."
The couple declined to comment.