Both have been out since the end of last season and England Under-21 international Luke Garbutt has been deputising at left-back in their absence during the Barclays Asia Trophy in Singapore.
Baines required ankle surgery after suffering a recurrence of an old problem in a game against Sunderland in May while Oviedo broke a metatarsal in training in April.
The duo have both been included in the Toffees squad for the upcoming pre-season trip to Scotland, which features friendlies against Hearts on Sunday and Dundee next Tuesday.
Martinez told the club’s website: “We have got some very exciting news with Bryan Oviedo and Leighton Baines joining the group for Scotland.
“They are raring to go as you can imagine. They are two pristine professionals and they are a similar profile of player, so they have been helping each other with their work. They are full of energy and desperate to join the group.”
One player who will not be travelling to Scotland is new signing Gerard Deulofeu, who joined the club on a permanent deal from Barcelona after a successful loan in 2013-14.
Deulofeu suffered a hamstring injury against Arsenal in Singapore but Martinez is confident the Spaniard will be fit for the start of the Premier League season.
Martinez said: “It’s not a real concern; it’s an injury that I don’t think will stop him starting the league campaign.
“His physicality is that he is a sprinter and we need to make sure he is fully recovered before he is back on the pitch.”