The 26-year-old goalkeeper joins the club from fellow National League side Ebbsfleet United and will look to continue his impressive form in-between the sticks.
Haigh had to overcome adversity last season, losing his spot in the Ebbsfleet starting eleven due to a tragic double leg break.
However, after the painful road to full fitness, he ended the season with two promotion medals after joining City on an emergency loan and starring in the play-off campaign.
Speaking to oxfordcityfc.co.uk, Haigh said: “I’m buzzing to be back!
“After my leg break and the frustrating start to the season, it was amazing for me to finish in the way we did and it made everything seem worthwhile.
“Now, with a full pre-season under my belt, I’ll be ready to go for the first game of the season. Hopefully we can surprise a few next season.”
Not many players can claim they’ve won promotion twice in the same season (and from the same division).
However, City’s new number one has admitted that it has only fuelled his hunger to succeed in the division above.
“I definitely wore both medals around my neck for a while,” he joked.
“It only sunk in a few weeks after we got promoted and I couldn’t have asked for a better summer.
“However, as soon as that game (the Promotion Final) had finished I was ready to go again and attack the league above.
“It’s going to be really enjoyable being an underdog in most of the games. It gives us a big carrot to go and get points and do well.
"I personally can’t wait and I know the boys can’t wait to get started."