Myriam El Khomri was hospitalised on Tuesday morning following a "minor illness".
The minister was set to appear on TV to be interviewed about her planned labour reforms that have proved deeply divisive and led to a torrent of criticism from both unions and within her own Socialist party.
She was also due to hold talks with union chiefs on Tuesday afternoon to discuss her bill.
All her engagements have since been cancelled.
News of her illness comes a day after the French Prime Minister agreed to delay the introduction of her bill to allow for more consultation with unions.
Labour reform is always a hot potato issue in France and regularly leads to protests and strikes whenever it comes up. A petition against El Khomri's bill has already garnered over 800,000 signatures.
While the government believes the reforms will help improve competitiveness of French companies and reduce the record unemployment levels, opponents believe they eat into workers rights and make it far too easy for employees to be laid off.
While El Khomri's name is on the bill many critics of the reform believe the real author of the reform is Prime Minister Manuel Valls, a man labelled the "Tony Blair of the Socialist Party" due to his business friendly stance.
Opponents have accused Valls of hanging the labour minister out to dry by allowing her to take all the flack and it appears to be taking its toll on her health.
Secretary of State Jean-Marie Le Guen criticised the way some politicians had harshly criticised El Khomri and called for restraint.
"I know she has been tired in recent weeks," he said.
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