An A-List tennis pro is suing a half dozen restaurant chains on behalf of consumers in the five boroughs for illegally adding automatic tips to smaller groups of diners.

Ted Dimond claims that Olive Garden, Red Lobster, Ruby Tuesday, Marriott Marquis Hotel and Applebee’s in midtown have all added 15 percent or more gratuities to his bills at least once.

A native New Yorker, Dimond, 47, runs the courts at Randall’s Island in the winter and teaches in the Hamptons during the summer. He helps actresses like Naomi Watts and fashion bigs like Vogue entertainment editor Jillian Demling brush up on their backhands at Sportime in Amagansett.

New York City law says that restaurants “may not add surcharges to listed prices,” except for groups of eight or more.

But Dimond claims the eateries regularly flout the rule by “price fixing” that “has jointly raised the prices of dining in restaurants while simultaneously lowering the quality of products and services.”

The result is millions in improper profits, the Manhattan Supreme suit says.

Dimond’s attorney, Evan Spencer, said his client also dines at more upscale restaurants where illegal tipping happens, but the joints named in the suit were the most egregious violators.

The legal papers note that when a Long Island man was arrested in 2004 for refusing to pay an 18 percent automatic gratuity, the district attorney tossed the charge, saying “a tip or gratuity is discretionary, and that’s what the courts have found.”

Dimond wants wronged customers to be recouped $50 plus $1,000 for “willful violations,” where restaurants trick diners into adding a second tip when one is already included.

The class action suit cites a 2009 Post investigation that found dozens of businesses including trendy La Birreria on Fifth Avenue had engaged in illegal tipping practices and were fined for the violation.

Half of the chains did not immediately return requests for comment.

But Marriott spokeswoman Cathleen Duffy told the Post that the Times Square hotel’s Crossroads American Kitchen and Bar charges 18 percent gratuity on parties of six or more and that the policy is clearly stated on the menu. She said she wasn’t aware that the law only applied to groups of eight or larger.

A rep for Red Lobster and Olive Garden said he’s looking into the allegations.