The company confirmed the temporary timetable, which was first introduced on January 3 due to the impact of Covid, is set to end.
The move is ahead of schedule, with the temporary timetable initially due to continue until February 6.
A normal winter service will return on the following routes:
Largs - Cumbrae Oban - Coll - Tiree Oban - Colonsay Wemyss Bay - Rothesay Gourock - Dunoon.
At the height of CalMac' s Covid problems, more than 20 per cent of staff were having to self-isolate.
On-board retail and food and drink offering will also reopen on Wednesday.
CalMac managing director Robbie Drummond said: “I am pleased to say that because of a significant drop in the number of staff unable to work we can now offer a full winter service on the majority of routes."