Photo courtesy of TCC

The $20.3 million sale of a double condominium at the St. Regis Residences, Boston this week sets a new high-water mark for residential real estate in the Seaport District.

The transaction for Units 19C and 19E includes a pair of 3-bedroom units spanning 5,525 square feet and a 167-square-foot terrace overlooking Boston Harbor.

The price represents Boston’s top residential sale of 2024 and the ninth highest in history, according to The Collaborative Cos.

The buyer will pay $184,522 a year in property taxes and the monthly homeowners’ fee is $12,692, according to a property listing. The buyer is Aria Seaport LLC, according to a Suffolk County deed filed Wednesday.

Developer Cronin Group of Boston hired TCC as broker in late 2023 to accelerate the pace of sales at the 22-story tower. The developers received $240 million in mortgage financing from Cottonwood Group in November for 69 unsold units and paid off the $320-million construction loan.

Michael Moynihan of The Collaborative Cos. represented The Cronin Group, developer of the 114-unit Seaport Boulevard condo tower that replaced a pair of waterfront bars.