The six-part first series starred Nicola Walker, Stephen Mangan and Anthony Head.
Legal drama series The Split will return for a second series.
The BBC1 programme, based on the London divorce law circuit, looks at modern marriage and divorce through the eyes of the Defoe family.
The high-flying Defoes work for their family law firm, apart from Hannah, played by Nicola Walker, who works for rival firm Noble & Hale.
The dramatic finale of the first six-part series ended with Hannah having to choose between her husband Nathan (Stephen Mangan) and former partner Christie (Barry Atsma), while the wedding between two other characters was marred by the death of the family’s estranged father Oscar (Anthony Head).
The Split also stars Meera Syal, Fiona Button, Stephen Tompkinson, Deborah Findlay and Annabel Scholey.
The show’s creator Abi Morgan said: “It’s a delight and a privilege to bring The Split back for series two and to submerge myself once more into the world of Noble, Hale and Defoe and the lives of Hannah and her sisters.”
She added that she thanks the “enthusiasm of viewers” and is excited for the show’s return in 2019.
Jane Featherstone, production company Sister Pictures’ executive producer, said: “I’ve been very proud to see Nicola Walker leading our incredible cast through six episodes of Abi Morgan’s beautifully crafted exploration of families and modern marriage, and I am thrilled that we’re going to be able to continue to explore their lives in even more detail in a second series.
“Expect things to get even messier for the Defoe sisters and those closest to them.”
Piers Wenger, controller of BBC Drama, said: “In its first outing Abi and the team at Sister Pictures crafted a series which felt bold, modern and original and quite unlike anything else on our screens.
“We are delighted that it is returning to BBC1 for a second series.”