If there’s a Marryin’ Sam in Arlington, that would be Gerald Williams.

From his basement office in a 1940s-vintage small-practice law building on Courthouse Square, the 82-year-old Williams performs “no appointment necessary” civil weddings that take under an hour.

Averaging 25-30 per week, Williams figures that since embarking on this labor of love in 1982, he has delivered the no-frills pronouncement to more than 71,000 couples.

“It’s a lot of fun, and makes people happy,” says Williams on a Thursday in which he’d conducted five before this visitor arrived. “It’s reasonably steady and not a whole lot of work, though you do have to sit here all day.”

Arlington attracts aspiring couples who lack the patience, money or devotion for a congregation wedding from all over the area. That’s because Virginia differs from Maryland and the District in that it requires no three-day waiting period and no blood tests, Williams explains. Also, D.C. offers no magistrates (Arlington has two others besides Williams), requiring a judge or religious celebrant.

The cost is $30 for the license and $50 for Williams’ ceremony, collectable “after they both have said `I do.’ ” The secular ceremony includes familiar phrases “to have and to hold” and “by the authority vested in me by the Commonwealth of Virginia.” He does quiz the couples briefly to gauge seriousness. But he also peppers his protocols with jokes, informing fidgeting participants that the reason he asked them to stand on a certain spot is that, should they answer questions incorrectly, is a trap door.

Many clients “tear up” during vows, Williams says, even grooms.

Born in Mississippi and raised in Arkansas, Williams served in the Marines before starting a career as an auditor for the U.S. Agriculture Department. In 1959, he was offered a raise if he would transfer to Washington.

Eventually he got the bug to go to law school and, like many in Arlington’s close-knit- postwar legal establishment, he went at night at George Washington University. “The all-day admissions exam cost $30, but I had missed the registration deadline,” Williams recalls. Luckily, there was a make-up, and he soon was auditing by day and going to class five nights a week for three-and-a-half years.

He was quickly in good company, partnering with Arlington judicial giant Harry Lee Thomas doing real estate and other specialties. (Williams continues to dabble in real estate law, but only for established clients.) In 1982, after his partners became judges, a deputy clerk mentioned a vacancy on the civil magistrate’s roster.

Williams had done divorce work but found it distasteful. (A quickie divorce practice works right in his same building). Married to the same woman for 52 years, he has the authority to advise clients that “it gets better every day.” But his incantations haven’t prevented some clients from returning to report that the marriage didn’t take.

Part of Williams’ job is to proofread marriage applications (now completed electronically), which avoids the hassle of a petition to correct.

In 2010, a pair of American University students arranged with Williams to film some clients taking the plunge. Their documentary is on YouTube under “Arlington Is for Lovers.”

Asked whether he performed same-sex ceremonies since they became legal in Virginia on Oct. 6, Williams said “Yes, but not many. Those couples seem to go to Magistrate Carla Ward.”