The strike will cause chaos for France's 4.5 million train passengers, with stoppages planned two days out of five until June 28 unless Macron drops his bid to force a major overhaul at state rail operator SNCF.
Staff at Air France, garbage collectors and some energy workers are also staging separate walkouts Tuesday in a growing atmosphere of social strife 11 months after Macron came to power.
Pensioners, students and public sector workers have already taken to the streets in recent weeks protesting against the 40-year-old centrist's widespread reform plans.
"In the most tense social climate since the start of the Macron presidency, there is a real risk of the discontent crystallising," the regional Charente Libre newspaper warned on Monday.
The rail strike officially started on Monday evening but it begins in earnest on what the media have dubbed "black Tuesday".
Only one high-speed TGV train out of eight is scheduled to run and one regional train out of five, spelling problems for companies across the country as staff struggle to get to work.
"I regularly travel between Lyon and Grenoble for work. The strike is going to raise huge problems for me," lawyer Perrine Fontana, 27, told AFP at the main station in the southern city of Lyon on Monday.
"I can understand the railroad workers to a certain degree, but their strike challenges the personal and professional lives of many people."
Three-quarters of Eurostar trains to London and Brussels will run and Thalys trains towards Belgium and the Netherlands will operate almost normally, but there will be none at all to Spain, Italy or Switzerland.
At Air France, managers say 75 percent of flights will operate despite the fifth strike over pay in little over a month, but further walkouts are planned for April 7, 10 and 11.
"We need to rid this country of its strike culture," Gabriel Attal, spokesman for Macron's Republic On The Move (LREM) party, told France Inter radio on Monday.
Macron says the SNCF, saddled with 46.6 billion euros of debt, needs to make major changes as EU countries prepare to open passenger rail to competition by 2020.
It is 30 percent more expensive to run a train in France than elsewhere in Europe, according to his government, which wants to strip new SNCF hires of special rail workers' status guaranteeing jobs for life and early retirement.
Unions accuse Macron, a centrist ex-investment banker, of seeking to "destroy the public railways through pure ideological dogmatism".
They fear that plans to turn the SNCF into a publicly listed company, even with the state owning 100 percent of shares, could eventually lead to the rail operator being privatised -- something the government denies.
The rail strikes are being seen as the biggest challenge yet to Macron's sweeping plans to liberalise the French economy and make it more competitive.
He managed to pass controversial labour reforms in October, but the length and severity of the rail strikes are already earning comparisons with British prime minister Margaret Thatcher's showdown with coal miners in 1984.
The industrial action is a major test, too, of how much influence France's once fearsome unions -- whose membership has plunged to just 11 percent -- still carry.
Some 48 percent of train drivers and other staff are set to join Tuesday's strike, according to SNCF management, with its chief Guillaume Pepy warning entire lines could be closed.