This is a calendar of all events which were part of either the Virginia Slims circuit or the Colgate Series in the year 1978, with player progression documented from the quarterfinals stage.

Also included are the Grand Slam tournaments, the 1978 Virginia Slims Championships, the 1978 Federation Cup and a number of events not affiliated with either tour.

The tournaments of the Colgate International Series were divided into four groups – AAAA, AAA, AA and A – based on prize money.

The total bonus pool for the Colgate Series was $675,000, an increase of $75,000 compared to the previous year, and was divided over singles ($540,000) and doubles ($135,000).

In order to be eligible for a share of the respective bonus pools players had to a) participate in a minimum of seven singles or three doubles tournaments and b) accept invitation for the series championships if qualified based on merit.