The former MSP described his punishment for lying to the courts during his successful defamation action against the News of the World in 2006 as "heartbreaking".
After being sentenced, he announced his intention to appeal against his conviction.
In a statement read outside court by his solicitor, Aamer Anwar, he said: "This multi-million pound prosecution will separate me from my wife and child and that will be heartbreaking.
"But I will continue to fight a system that protects the real criminals - the rich and powerful."
After a three-month trial at the High Court in Glasgow, Sheridan, 46, was found guilty in December of lying about the newspaper's claims that he was an adulterer who visited swingers' clubs.
Sheridan's wife Gail, who has vowed to stand by her husband, was also accused of lying to the jury at the Court of Session in Edinburgh, but she was acquitted when the Crown dropped the case against her last month.
Mrs Sheridan sat in the front of the courtroom, as close as possible to her husband, as the judge Lord Bracadale delivered his sentence.
And she led the politician and former Celebrity Big Brother contestant's family, friends and comrades in a one-fisted salute as he was led, handcuffed to the cells.
Outside court, Mrs Sheridan said: "Tommy has dedicated his life to helping others.
"The real reason why he's been imprisoned today is because he has fought injustice and inequality with every beat of his heart.
"But it won't be long before Tommy is back stronger and continuing the fight."
Sheridan's mother Alice also maintained her son was innocent.
She said: "He should never have been there. He is an innocent man - it will be proved he is innocent."
Before he was sentenced, Sheridan, who conducted his own defence for most of the trial, said: "I remain a passionate socialist and am determined to put to positive use my time in custody.
"On my release I will return to fight for justice, for equality and for peace."
He added: "My primary concern is the devastating effect of custody on my family."
Throughout the 12-week perjury trial Sheridan maintained his innocence, claiming he was the victim of a "vendetta" by the police and a "conspiracy" involving the News of the World and colleagues within the Scottish Socialist Party (SSP).
He now plans to sue the News of the World over allegations his mobile phone was hacked by private investigator Glenn Mulcaire.
In a statement read out by Mr Anwar, Sheridan said: "Andy Coulson may have resigned for the second time but if he and others are not above the law then it is time that they faced justice."
But the News of the World said the conviction and sentence was a "just outcome".
The newspaper has since lodged an appeal against the defamation verdict and the £200,000 awarded to Sheridan following his conviction.
The jury ultimately convicted him of five of six allegations in a single charge of perjury against him, relating to his evidence during the civil case.
In doing so, they found him guilty of lying about an affair with SSP member Katrine Trolle in 2005 and a trip to Cupid's with her, Andrew McFarlane, Gary Clark, and News of the World journalist Anvar Khan on September 27 2002.
Lord Bracadale told Sheridan his decision to pursue the News of the World for defamation "brought the walls of the temple crashing down not only on your own head but also on the heads of your family and your political friends and foes alike".
He said: "You embarked on an action in the Court of Session knowing that for it to be successful you would require to tell lies under affirmation.
"You went on to commit perjury in the course of successfully pursuing that action, as a result of which you were awarded a very large sum of damages.
"In these circumstances the only appropriate sentence, as you yourself recognise, is one of imprisonment."
As he was led away to the cells, Sheridan turned to his family - including his wife Gail, mother Alice, and sister Lynn, and said simply: "Take care. All the best."
