Paris Mayor Bertrand Delanoe performed the ceremony at the municipal offices in central Paris where hundreds of fans and paparazzi had gathered to get a glimpse of the glamour couple.
Longoria, 32, dressed in a short pink dress with black trim, arrived for the ceremony in a limousine while Parker, 25, showed up separately, accompanied by French football player Thierry Henry, who was rumoured to be his best man.
The civil ceremony is the prelude to a church wedding to be held tomorrow at the Saint-Germain-l'Auxerrois church, not far from the Louvre museum in central Paris.
The newlyweds then join their Hollywood friends for a lavish party at Vaux-le-Vicomte, a 17th-century chateau south-east of Paris.
Paris Mayor Delanoe made no comment to the hordes of reporters as he left the municipal building, but he earlier said he was delighted to officiate for the wedding of the couple that he described as “friends”.
“There is quite a frenzy surrounding them, but for me they are Eva and Tony, two very likeable young people who love each other and are enjoying an important moment in their lives,” Mr Delanoe said ahead of the ceremony.
“I think it's quite nice of them to ask me to perform the marriage,” he said.
"I will do it with their feelings, their life and their happiness in mind and certainly not by putting on a show."
Longoria and Parker have kept their guest list secret, but media reports suggest that actors Michael Douglas, Catherine Zeta-Jones and Jamie Foxx, singer Lionel Richie and Sting will be there.
A private jet carrying the bevy of beauties from the hit TV show - Teri Hatcher, Felicity Huffman and Nicolette Sheridan - landed in Paris yesterday, but Marcia Cross, who plays the conniving red-headed Bree Van de Kamp, was unable to attend, according to Le Parisien newspaper.
Parker told Le Parisien he left the entire preparations for the wedding to his fiancee - “except for the food and the music” - after she advised him to “keep his focus on the NBA playoffs”.
“I'm the luckiest guy in the world,” said the San Antonio Spurs guard, who was Most Valuable Player in this year's NBA finals.
According to the rumour mill, Beverly Hills wedding planner to the stars Mindy Weiss spotted Vaux-le-Vicomte after Longoria said she wanted a “fancy wedding” and loved the romance of France.
Rights to wedding photographs have been negotiated by OK! magazine for a reported fee of $US2 million ($2.34 million).
Longoria and Parker held bachelor and bachelorette parties in the French Riviera resort of St Tropez earlier this week.
Born in Belgium to an African-American basketball professional and a Dutch model, Parker was brought up in Rouen, west of Paris, and started his sporting career in the US in 2001.
He is the first European to be named Most Valuable Player in the NBA finals.
Longoria, a Texan, has long been a Spurs fan, and is a regular at his matches.
They got engaged last November.
