Clinton and Trump both won at least six of 11 state primaries of the the Democratic and Republican parties as the possibility of a November presidential election showdown between the two seemed likely.
68-year-old Clinton, who is seeking to become the first women president of the United States, won Democratic Party's primaries in six states of Texas, Georgia, Virginia, Alabama, Massachusetts and Tennessee.
Her only primary rival Senator Bernie Sanders of Vermont won in his home state and in Oklahoma.
Texas Senator Ted Cruz, who is the Republican Party favourite, won in his home state and also in Oklahoma.
Florida Senator Marco Rubio, said to be the establishment candidate for the Republican Party, was leading in Minnesota.
After a string of wins in the Super Tuesday primaries, Trump, at a press conference in Florida, claimed that he is on his way to win the party's presidential nominee as he is way ahead of the other candidates.
"So I think we're going to be more inclusive, more unified and a much bigger party and I think we're going to win in November," he said.
In his victory speech, Cruz called all the other candidates to drop out of the race claiming that he is the only one who can defeat Trump in the Republican presidential primaries.
In her victory remarks, former Secretary of State Clinton set her sights on the possible clash with Trump for the presidency.
She attacked Trump's pledge to "make America great again", saying, "America never stopped being great!".
"It's clear tonight that the stakes in this election have never been higher, and the rhetoric we're hearing on the other side has never been lower," she said amid applause from supporters in Miami.
Almost 600 Republican delegates were up for grabs today,
Some 865 Democratic delegates are at stake, 36 per cent of those needed to win.
"It's good to be home," said a tired-sounding Sanders as he celebrated a thumping win in his home state Vermont, by a margin of 86-13 with 60 per cent of votes counted.
"I am so proud to bring Vermont values all across this country. Tonight you are going to see a lot of election results come in...But remember this is not a general election, this is not winner takes all. By the end of tonight we are going to win many hundreds of delegates," he said.
The US media was indicating towards a Clinton and Trump clash.
"Trump supercharged his hostile takeover of the Republican Party on Super Tuesday, scoring big wins in at least six states as he threatened to break away from his GOP rivals in the delegate chase," the Politico reported.
According to The Washington Post, with so many victories so far, Trump is the preferred Republican presidential candidate.
"Going back to 1960, well before all of the states regularly weighed in on the nomination, no Republican nominee has won the states of Alabama, Georgia, Massachusetts, Tennessee, New Hampshire, Nevada, Virginia and South Carolina," The Post said.
Clinton has secured three wins in the first four early-voting states and has led significantly among blocs of black voters there.
Trump has stunned the Republican establishment to become the party's front-runner. Despite his controversial policies on immigration, the former reality TV star has been consistently polling well above his rivals -- Cruz, Rubio, Kasich and retired neurosurgeon Ben Carson.
Both Senators Cruz and Rubio have ramped up their anti-Trump rhetoric over the past week, in a bid to halt his commanding lead in the race.
