Sabalenka, ranked No.6 in the world, put paid to Shelby Rogers 7-6 (8-6) 6-0, as the favourite in Netherlands reached her second singles final this year.
World No.30 Alexandrova had little difficulty against Veronika Kudermetova as she triumphed 6-3 6-1 to reach her first singles final of the season.
Sabalenka and Alexandrova have split four previous meetings with two wins apiece, with the latter taking the most recent clash in straight sets at the Moscow quarter-finals last year.
No.7 seed Beatriz Haddad Maia stunned favourite Maria Sakkari in the quarter-finals to tee up the last-four clash with Tereza Martincova in Nottingham.
The Brazilian raced out the blocks once more to progress past Martincova, with the former 6-3 4-1 up before the Czech retired with injury.
Rain stopped play in the second semi-final between Viktorija Golubic and Alison Riske with the scores level at one set each.
No.6 seed Riske capitalised from that point on to edge past Golubic 6-3 4-6 6-3.
