Although it fell short of a predicted landslide, Macron's Republic on the Move (REM) and its allies won 350 seats in the 577-seat National Assembly on Sunday, AFP reported.
The election was being closely watched in Europe and around the world to see if France's youngest-ever leader would secure a mandate to push through his pro-EU reform agenda.
The new body will be nearly six years younger on average, have a record 223 women lawmakers, and will be strikingly less politically experienced.
The trailblazing party that 39-year-old Macron founded just 14 months ago has caused a political earthquake even if the winning score was considerably lower than the 470 seats predicted by some pre-vote surveys.
"A profoundly renewed political generation takes over the reins of legislative power," wrote editorialist Alexis Brezet in the right-leaning daily Le Figaro.
Macron's confident start at home, where he has concentrated on trying to restore the lost prestige of the president, and his bold action on the international stage has inspired a raft of positive headlines.
Macron wants to use his majority in parliament to pursue his agenda of loosening labor laws and overhauling France's social security system.
He has already had little pushback on his stated intention to use executive orders to push through reforms without parliamentary debate -- though street protests over the erosion of cherished workers' rights such as those seen last year are considered likely.
The parliamentary boost also strengthens Macron's hand on the European stage as the EU heads into negotiations on Britain's departure from the bloc.
The staunch europhile – in stark contrast to presidential rival Marine Le Pen – will take part in his first EU summit Thursday and Friday in Brussels.
He wants a leadership role in countering the kind of nationalism that far-right leader Le Pen represents, which spurred the Brexit vote and helped propel Donald Trump to the US presidency.