Mr Mondale was 39th US president Jimmy Carter’s running mate during his successful 1976 election bid and defeat in 1980. He died in Minneapolis on Monday. Mr Carter referred to Mr Mondale the “best vice-president in our country’s history”.
In a statement, Mr Carter described him as “an invaluable partner and an able servant of the people of Minnesota, the United States and the world”.
The Democrat added: “Rosalynn and I join all Americans in giving thanks for his exemplary life, and we extend our deepest condolences to his family.”
Former President Barack Obama hailed the progressive changes undertaken by Mr Mondale in a tweet.
He wrote: “Walter Mondale championed progressive causes and changed the role of VP — so leaders like @JoeBiden could be the last ones in the room when decisions were made.
“In selecting Geraldine Ferraro, he also paved the way for @VP to make history. Michelle and I send prayers to his family.”
Vice President Kamala Harris issued a statement saying she would miss Mr Mondale, as she sent her condolences to his family.
She said: “Vice President Mondale was so generous with his wit and wisdom over the years.
“I will miss him dearly, and my heart is with his family today.
“I hope they find comfort knowing that he is with his beloved wife, Joan, and daughter, Eleanor, now — and that his legacy will live on in all of us.”
Mr Mondale ran for president in 1984 but saw a landslide defeat against Ronald Reagan.
The electoral vote was 525-13 for Mr Reagan, with Mr Mondale only carrying his home state of Minnesota and the District of Columbia.
Following the election, Mr Mondale said: “I did my best.
“I think you know I’ve never really warmed up to television.
“In fairness to television, it never really warmed up to me.”