Josh Portis was born 14 July 1987 in the state of California, and graduated early from William Howard Taft High School in Woodlands Hills California. His mother, Patricia Portis was born in Mobile, Alabama with 11 siblings. Josh's Grandfather, A.D. Portis, was vice president of Alabama State Docks, before his passing.

Coming out of high school, he was recruited by Florida, Maryland, Washington and many other D1 schools. Josh was ranked 4th dual threat QB in the nation by Rivals. He was also voted Los Angeles High School QB of the year. Josh was a back-up QB to Chris Leak at Florida and played QB at Maryland while receiving his Bachelor Degree. After receiving his bachelor degree at Maryland, Josh went to Cal U. to work on his Master Degree. He is the first player at Cal U. to be invited to the NFL Combine.

Early years
Portis grew up in Woodland Hills in Los Angeles, California with his mother Patricia Portis. He is a cousin of Washington Redskins running back Clinton Portis. Portis attended William Howard Taft High School where he was a three-year letter winner at quarterback. He threw for 2,294 yards, 36 touchdowns, and seven interceptions, and ran for 865 yards and 13 touchdowns. As a senior, he was named an all-state player, league offensive player of the year, and a Los Angeles first-team all-city player. Scout.com assessed him as the fifth-best dual-threat quarterback in the nation. He was highly recruited out of high school and received offers from Florida, Maryland, Kansas State, Oregon, Oregon State, Utah, and Washington.

College Football
Portis attended college at Florida for one season and saw action in six games. In 2005, he made six out of 11 completions for 81 yards. He threw one interception and was sacked three times. He was Florida's fourth-leading rusher with 163 yards on 24 carries. He transferred to Maryland in 2006 and was required by NCAA rules to sit out for a season. He completed one of three pass attempts for 4 yards and made 31 carries for 186 rushing yards and a touchdown. His playing time decreased throughout the season, seeing action on just eight plays in the last half of the season.

On January 7, 2009, it was announced that Portis would transfer to the California University of Pennsylvania in the spring semester. Since the school competes at the Division II level, he has two years of eligibility remaining with the California Vulcan's. He started the season-opener, in which eighth-ranked California lost to unranked Saginaw Valley State, 23–17 and recorded 14 completions on 31 attempts for 145 yards and two interceptions and led the team in rushing with 12 carries for 82 yards. In that one game, he exceeded his previous combined career pass attempts of 14. After dropping the second game, 17-10, to sixth-ranked Bloomsburg University, Portis turned his team around and threw for 202 yards in a 30-23 Cal U win over West Chester University. Portis now leads the Pennsylvania State Athletic Conference with 18 touchdown passes, a passer rating of 179.4, and led the Vulcan's to their 5th straight PSAC West Championship.