Character actor Hugh O'Brian, best known as the star of the TV series "The Life and Legend of Wyatt Earp," is to be at a fundraising reception tonight at the Old Ebbitt Grill to benefit the Hugh O'Brian Youth Foundation. The invitation-only, $125-a-person reception will help sponsor a delegation of D.C. high school sophomores to attend a three-day youth leadership seminar here in March. The reception is being cosponsored by Senate Majority Leader Robert Dole, House Minority Leader Robert H. Michel, Mayor Marion Barry and D.C. Del. Walter Fauntroy . . .

When Newsweek and Time magazines hit the newsstands yesterday, both had cover stories on cocaine. It happens sometimes that cover topics coincide and readers wonder how it happens. A Newsweek spokesman maintained that it wasn't surprising or unusual. Mike Luftman, Time's press information manager, also said it wasn't surprising, given the kind of news stories last week about drug trafficking. "And besides," he said, "great minds think alike" . . .

The National Endowment for the Arts has been voted an honorary award by the Academy of Motion Picture Arts and Sciences "in recognition of its 20th anniversary and its dedicated commitment to fostering artistic and creative activities and excellence in every area of human genius . . ."

If you're riding in a Washington cab and the driver says he's Mel Krupin's father and recommends his son's restaurant, it's a good story, but it's not true. Valerie Phillips, associate director for political affairs at the U.S. Chamber of Commerce, had that happen to her. The driver gave her a card to Krupin reading, "Free drink, your dad." Krupin laughed when asked about it yesterday. "I've even had people say, 'What are you doing having your father hacking at night when you own a big restaurant?' " He said the cab driver is a friend and uses the "Dad" card to let Krupin know who recommended his restaurant. Krupin's father is retired and lives in New York . . .

In the those-things-happen category, yesterday's New York Daily News was dated Feb. 20. That newspaper has always been fast, but a day ahead of the news? . . .