The judgement was a "victory for every Indian", Mr Gandhi said on Twitter.
"Welcome the SC verdict upholding Right to Privacy as an intrinsic part of individual's liberty, freedom and dignity. The SC decision marks a major blow to fascist forces," he tweeted.
It was a "sound rejection" of the BJP's ideology of "suppression through surveillance", Mr Gandhi said.
In a landmark decision, the Supreme Court today unanimously declared that the right to privacy was a fundamental right under the Constitution.
A nine-judge Constitution bench headed by Chief Justice J S Khehar ruled that the right was "an intrinsic part of the Right to Life and Personal Liberty under Article 21 and the entire Part III of the Constitution".
The ruling on the highly contentious issue dealt with petitions challenging the Centre's move to make Aadhaar mandatory for people seeking to benefit from various social welfare schemes.