Joe acts an older brother figure to Cody, who inherited the trait of Reliability from him.
T.K. is Cody's DNA Digivolution partner.
In spite of occasional arguments, Cody and Davis and appear to have a fairly stable friendship. This is shown by the fact Cody rarely challenges Davis' leadership or make disparaging comments about his personality, certainly much less often than the other regular characters. Davis also shows a certain level of respect for Cody that he doesn't for the rest of the group and often comments (if sarcastically) at Cody's maturity and intelligence. Whilst Davis often disregards protests from Yolei and T.K., he gets noticeably agitated when Cody takes the opposing side to him. The two also get along well when they are both left in jail by Deputymon alone with each other.
Yolei lives in the same apartment building as Cody, and the two are rather close friends even before becoming DigiDestined.
Initially Cody does not take well to Ken because of his past as the Digimon Emperor. Cody is the last to accept Ken into the group, and even then there is a noticeable resentment between the two, to the point that an attempt to reconcile them ends up splitting the group. In the end, however, the two make up as Cody begins to learn to forgive and understand Ken's perspective more.