Pop-singing sensation Justin Timberlake is buying a Manhattan penthouse — and not for a song.

The boy-band legend and his wife, MTV Movie Award-winning actress Jessica Biel, are the latest celebs to shack up inside star-studded 443 Greenwich St. — a luxury CetraRuddy-designed condominium conversion in Tribeca — according to the Real Deal.

While the couple reportedly bought a penthouse, it’s not clear which one — simply because there’s more than one in the building on the market.

The Real Deal surmises that Timberlake, Biel and toddler son Silas Randall will move into a 5,375-square-foot, four-bedroom penthouse that asked a cool $27.5 million — in part because it went into contract this month.

(The other possibilities, which are two different penthouses that are publicly listed, are a 5,000-square-foot unit with three bedrooms and 4 ¹/₂ bathrooms that was most recently asking $20.5 million that went into contract in October 2016 and a $55 million, 8,569-square-foot five-bedroom that remains on the market as of publication.)

Timberlake and Biel have reportedly been house-hunting in New York City for several months. Before sealing the deal at 443 Greenwich, sources told The Post that the couple eyed a 5,704-square-foot triplex penthouse at 12 E. 13th St., which originally asked $28.5 million in 2013, but is now listed for a majorly price-chopped $16 million.

The couple is familiar with the insanity of the celebrity-real-estate search; fans have surprised them at apartment viewings at least once.

Perhaps Timberlake and Biel landed on 443 Greenwich because it’s already lured other star buyers — including couple Ryan Reynolds and Blake Lively, as well as Jennifer Lawrence. British Formula One driver Lewis Hamilton bought another one of 443 Greenwich’s eight penthouses, which asked $54 million.

Developer Nathan Berman of MetroLoft declined the Real Deal’s request for comment on Timberlake and Biel’s purchase, but said a whopping 90 percent of buyers at the 53-unit building are “household names.”

One other big-name buyer at 443 Greenwich included Mike Myers — of “Saturday Night Live” and “Austin Powers” fame — who recently flipped his never-lived-in four-bedroom there at a loss. Myers scored $14 million in the sale — $1 million below its $15 million ask and $675,00 below what he paid for it in December.

Building amenities at 443 Greenwich include a 24-hour doorman, a shared 71-foot pool, a temperature-controlled wine cellar and a 5,000-square-foot roof terrace.