Although it is commonplace to apply the title of Savior to Jesus, Paul uses it to refer to God the Father as well.
A relevant parallel
Compare to 1 Timothy 1:1:
Paul, an apostle of Jesus Christ by the commandment of God our
Saviour, and Lord Jesus Christ, which is our hope;
I do not doubt there are those who would interpret this passage differently, but I find the Greek to clearly describe God as our Savior and Jesus Christ as our hope--Paul produces a somewhat poetic couplet:
Θεοῦ Σωτῆρος ἡμῶν
Χριστοῦ Ἰησοῦ τῆς ἐλπίδος ἡμῶν
God the Father
That it is God the Father that Paul has in mind here is evident by comparing this verse with the openings to several of Paul's other epistles, e.g.
Paul, and Silvanus, and Timotheus, unto the church of the
Thessalonians which is in God the Father and in the Lord Jesus Christ:
Grace be unto you, and peace, from God our Father, and the Lord Jesus
Christ. (1 Thess 1:1)
(See also 2 Thess 1:1 & Galatians 1:1 for further examples)
Who is the Savior?
"Savior" means one who saves. In this general sense there can be many who are saviors because they participate in the work of salvation--this I believe is what Obadiah (poor guy never gets quoted so I thought I'd give him a shout out) has in mind:
And saviours shall come up on mount Zion to judge the mount of Esau;
and the kingdom shall be the Lord’s (Obadiah 21).
There are many who participate in bringing a soul to salvation, including those who labor to preach, love, serve, and correct (see Romans 10:14-18). But there is something transcendentally greater taking place in the salvation of a soul.
Let's imagine there's a man who has been shipwrecked--we'll call him Paul. Paul manages to send a message that he's been shipwrecked and has taken refuge on an island--we'll call it Malta. Somebody in Rome receives Paul's message and sends a trusted captain out in a boat to rescue Paul (yes I realize Acts 28 didn't really play out quite this way =) ).
Who saved Paul--the person who got the message and organized the rescue, or the person who actually came to get him? The answer is both.
1 John 4:14 favors the common usage of the term Savior to apply to Jesus:
And we have seen and do testify that the Father sent the Son to be
the Saviour of the world.
But it was the Father who sent Jesus, so of course it is appropriate to honor the Father's role in Salvation by referring to Him as a Savior--it is His plan of salvation.
Is there more than one Savior? To build upon my metaphor, two Saviors would seem to be a fair description if more than one rescue boat had been sent. But the Father sent one and only one rescue boat--God the Father and Jesus play distinct roles but were completely aligned on the rescue plan.
Although we could define "savior" broadly to include many people--including whoever taught us the gospel--there is an important scriptural sense in which there is only one Savior: there is only one in whose name Salvation comes. Speaking of Jesus, Peter taught:
Neither is there salvation in any other: for there is none other name
under heaven given among men, whereby we must be saved. (Acts 4:12)