Hahn and Uchitel were granted a marriage licence last Saturday in Clark County, Nevada, according to documents obtained by TMZ.
The couple apparently tied the knot less than 24 hours later at 8.58am local time on Sunday morning.
The Celebrity Rehab star and Hahn, a businessman, have been living together in San Francisco for the last several months.
In July, it was reported that Uchitel once dated Jamie Dingman, who is currently involved with Woods's ex-wife Elin Nordegren.
Uchitel's work as a private investigator will be featured in an upcoming reality series.
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