For $21,000 a month, you can rent an apartment at the legendary, landmarked Apthorp that was most recently home to singer and Oscar-winning actress Jennifer Hudson.

The four-bedroom, 3½-bathroom Upper West Side corner unit, at 2211 Broadway between West 78th and West 79th streets, measures 3,000 square feet. Hudson, who made her name on “American Idol,” won an Oscar for her role as Effie White in “Dreamgirls.”

She is currently working on “Monster,” an independent drama that she is starring in with A$AP Rocky and Kelvin Harrison Jr., of “The Birth of a Nation.”

Co-producers include Spike Lee’s wife, Tonya Lewis Lee, and Nikki Silver, of Tonik Productions.

The prewar apartment is on the 11th floor.

It features charming details throughout, including crystal chandeliers, moldings and fireplaces.

There’s also a large living room, a formal dining room and a chef’s kitchen.

Building amenities include a gym with a steam room, sauna and a yoga studio.

There’s also an acclaimed central courtyard.

The listing broker is Randy Smith of Citi Habitats.