The former Beverly Hills, 90210 star, 41, has split from San Francisco-based media exec Michael Shimbo, a source confirms to PEOPLE. They dated for three months.
The pair made the decision to end things while in Austin, Texas, to watch Formula One's U.S. Grand Prix over the weekend, E! News reports.
In September, Garth went public with her relationship, posting an Instagram shot of her and Shimbo, with the caption "#luckylady."
A rep for Garth declined to comment on the Shimbo split.
The actress – who finalized her divorce from Peter Facinelli in June – was also recently linked to Big Gigantic drummer Jeremy Salken.
Up for next for Garth? The TV movie Holidaze, airing Dec. 8; as well as a new pilot, Mystery Girls, with Tori Spelling.
Reporting by MONICA RIZZO
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