A 185 cm ruckman, Johnson began his senior career playing with Port Melbourne in the VFA in the 1950s.

He won a record five best and fairest awards at Port Melbourne, in an era where the team reached eight consecutive grand finals (winning only once).

He won the J. J. Liston Trophy for his efforts during the 1952 season and twice earned All-Australian selection: the first time was in the 1953 Adelaide Carnival where he was named in what was the inaugural All-Australian team, and he was selected as captain in the 1956 Perth Carnival team.

He had immediate success by winning the club's best and fairest, and finishing fourth in the Brownlow Medal count the following year.

[2] The Frank Johnson Medal, named in his honour, is awarded by the Victorian Football League to its best player in each interstate representative match.