The deal, which was not preannounced, was completed Thursday, one month after the final agreement was signed by the two companies.
Details of the transaction were not disclosed, but a spokeswoman confirmed that there will not be any layoffs among the 48 Signature employees working at the firm's Norfolk, Va., headquarters and two other Virginia offices.
Baltimore-based Brown Advisory, which has eight offices and 600 employees working with clients in the institutional, endowments, foundations and high-net-worth markets, is expected to benefit from Signature's focus on family office services.
With that in mind, Signature spokeswoman Andrea Ayres said that the "Signature name will stay intact," at least for the time being.
Signature was founded in 1994 by Anne Shumadine and Susan Colpitts, and was ranked among InvestmentNews' Best Places to Work in 2018.
In a statement, Signature president and Chief Executive Randy Webb said the two companies "share similar cultural tenets."
"The combination with Brown Advisory is perfectly aligned with the expectation and intention of Signature's founding," Mr. Webb said. "The combined resources and expertise of Signature and Brown Advisory will enhance the platform for our industry-leading multi-family office service."