The World Group I play-offs were four ties which involved the losing nations of the World Group and the winning nations of the World Group II. Nations that won their play-off ties entered the 2019 World Group, while losing nations joined the 2019 World Group II.

Participating Teams
Australia	Belarus	Belgium	Italy
Netherlands	Romania	Slovakia	Switzerland

Belarus vs. Slovakia

Belarus 3	Chizhovka-Arena, Minsk, Belarus[1] 21–22 April Hard (indoor)		Slovakia 2
1 2 3 1 Aliaksandra Sasnovich Jana Čepelová 78 66 7 5     2 Aryna Sabalenka Viktória Kužmová 2 6 6 2 65 77   3 Aryna Sabalenka Anna Karolína Schmiedlová 6 3 6 4     4 Aliaksandra Sasnovich Viktória Kužmová 1 6 63 77     5 Vera Lapko / Lidziya Marozava Viktória Kužmová / Anna Karolína Schmiedlová 6 3 6 4

Romania vs. Switzerland

Romania 3	BT Arena, Cluj-Napoca, Romania[2] 21–22 April Clay (indoor)		Switzerland 1
1 2 3 1 Simona Halep Viktorija Golubic 6 3 1 6 6 1   2 Irina-Camelia Begu Timea Bacsinszky 6 4 6 1     3 Simona Halep Patty Schnyder 6 2 6 1     4 Irina-Camelia Begu Viktorija Golubic       not played 5 Mihaela Buzărnescu / Sorana Cîrstea Viktorija Golubic / Jil Teichmann 6 0 0 6 [6] [10]

Australia vs. Netherlands

Australia 4	WIN Entertainment Centre, Wollongong, Australia[3] 21–22 April Hard (indoor)		Netherlands 1
1 2 3 1 Samantha Stosur Lesley Kerkhove 5 7 61 77     2 Ashleigh Barty Quirine Lemoine 6 0 6 2     3 Ashleigh Barty Lesley Kerkhove 6 4 6 2     4 Daria Gavrilova Quirine Lemoine 6 3 6 2     5 Destanee Aiava / Daria Gavrilova Lesley Kerkhove / Demi Schuurs 6 3 6 2

Italy vs. Belgium

Italy 0	Valletta Cambiaso ASD, Genoa, Italy[4] 21–22 April Clay		Belgium 4
1 2 3 1 Jasmine Paolini Elise Mertens 1 6 5 7     2 Sara Errani Alison Van Uytvanck 4 6 78 66 2 6   3 Sara Errani Elise Mertens 3 6 1 6     4 Jasmine Paolini Alison Van Uytvanck       not played 5 Deborah Chiesa / Jasmine Paolini Kirsten Flipkens / Elise Mertens 1 6 4 6