The media mogul, who mentored Lohan last year (13) and gave the actress her own reality TV series, jetted to the capital to show her support as the Mean Girls star made her West End debut in David Mamet's satire.
Winfrey attended a performance of the show at the Playhouse Theatre on Saturday night (04Sep14) along with 12 Years A Slave actress Lupita Nyong'o.
Lohan posted a picture on her Instagram.com page showing herself posing backstage with Winfrey, adding in the caption, "The definition of a blessing. Thank you @oprah and @Lupita_Nyongo for seeing the show tonight (sic). Love you xx."
She also took to Twitter.com to thank the stars for their support and she described Winfrey as her "fairy godmother".
Lohan's performance in the play was well received by critics following opening night on Thursday (02Oct14).