Walker, also seen on Broadway in Cat on a Hot Tin Roof, Les Liaisons Dangereuses and Inherit the Wind, will star as Travis Parker opposite Teresa Palmer ("The Ever After") as Gabby Holland.
Ross Katz will direct from a screenplay by Bryan Sipe. The film covers the couple's decade-long love affair.
Nicholas Sparks Productions' Sparks and Theresa Park are partnering with Peter Safran to produce, and Jason Constantine and Eda Kowan are overseeing for Lionsgate.