Officials announced the bout Tuesday. The televised card will take place inside Sprint Center.
For Nelson (22-13), it will mark his first appearance since he was suspended six months by a Brazilian sports court for kicking referee John McCarthy immediately after a fight. Nelson, 40, originally was suspended for nine months, but received a reduced penalty after issuing a public apology to McCarthy.
Nelson knocked out Antonio Silva in the second round of a heavyweight contest on Sept. 24 in Brazil. He was angry at McCarthy for not stopping the bout sooner. It marked the 14th knockout of Nelson's career.
Volkov (27-6) is coming off a split-decision win over Timothy Johnson in his UFC debut in November.
The Russian heavyweight won the Bellator championship in 2012, before losing in his first attempted defense. He signed with the UFC last year.