No, Satan is not omnipresent. That is, he is not present everywhere at once. The devil is limited to being in one place at a time.
Because Satan is a finite, created being, omnipresence cannot be attributed to him (Ezekiel 28:15). Christ created all things (Colossians 1:16), including the devil—although Satan was not originally an evil being. Satan has boundaries and is not infinite in any way, including in his presence. Only God is omnipresent (Psalm 139:7–11).
The book of Job reveals that Satan can travel to heaven and roam about the earth (Job 1:6). Although the devil can go to different locations, he is never described as present everywhere. Satan and his demons do have abilities that humans do not, but they are limited nonetheless. The demons had to leave the possessed man of the Gerasenes in order to enter the pigs (Luke 8:33), and Satan is described as leaving Jesus in the desert after tempting Him (Matthew 4:11). If he left Jesus, he was no longer present with Jesus. It is evident that Satan is limited in space and time.
Because the devil is a deceiver (Revelation 12:9), he tries to make people believe that he is omnipresent like God. Satan fell because of his sin of pride and desire to be like God (Isaiah 14:13–14). Therefore, it is understandable that the devil would want to deceive humans into believing that he is present everywhere. It may seem as if Satan is present everywhere at the same time because of widespread spiritual attacks, but that is an illusion. Satan has numerous demons in his service who also carry out his schemes (Matthew 12:24; Ephesians 6:12). Charles Ryrie comments: “The very large number of demons may make them seem to be everywhere present, though that is not so. Yet Satan working with them can use their number to attempt to promote his plans everywhere” (Basic Theology, Moody Publishers, 1999, p. 186).
Believers need to be aware of Satan’s schemes and his desire to do harm (2 Corinthians 2:11; Ephesians 6:11). Even though Satan is a powerful enemy, he is not God and he is not omnipresent. God alone is omnipresent, and God alone is sovereign (Jeremiah 23:24; Psalm 115:3). Satan may be roaming the earth now, but one day he will be confined to the lake of fire, where he “will be tormented day and night for ever and ever” (Revelation 20:10).