Gujral's body has been kept at his 5 Janpath residence here for the public to pay respects. Leaders cutting across party lines also visited his residence to pay their homage.
92-year-old Gujral died at a private hospital in nearby Gurgaon after a brief illness yesterday.
The Prime Minister and his wife arrived at his residence this morning and paid floral tributes.
In his message, Singh said, "In the sad demise of Gujral, our country has lost a freedom fighter, a great patriot and a great scholar statesman. I join the nation in expressing our grief and sorrow at the demise of great son of India."
Union Ministers A K Antony, Anand Sharma and Farooq Abdullah, Punjab Chief Minister Prakash Singh Badal, BJP's Ananth Kumar and LJP's Ramvilas Paswan were among others who visited the residence.
Gujral will be cremated in Smriti Sthal later in the day.
Union Telecom Minister Kapil Sibal remembered Gujral as a man of "extraordinary humility".
"A man who always spread the message of peace, not just within neighbourhood but throughout the world. A gentleman politician who had empathy in his heart and a great intellect of the mind - a very rare combination. And he carried this with greatest of humility," he said.
JD(U) chief Sharad Yadav said he had a long relationship with Gujral. "We had made him fight from Patliputra seat for the first time when he contested Lok Sabha election. Then we brought him to Rajya Sabha from Bihar.
"He was well balanced in his word and also in his life. He always rightly interpreted the world affairs. I was party president when he was the Prime Minister," he said.
Commerce Minister Anand Sharma said Gujral served the country with distinction and he will be remembered with respect by the people of India.