The agency was appointed after a pitch process that started in December last year and was conducted through AAR.
TCA's brief covers all on- and offline communications to promote the school's education programme to students and corporate buyers.
London Business School has previously worked with agencies including Gyro and Tequila\London. It appointed Mindshare last year to handle its media planning and buying.
In 2009, the agency Serious Ideas won an IPA Effectiveness Award for its social media campaign for London Business School. The activity focused on recruiting students to a new Masters programme at the school.
Adam Leigh, the chief executive of TCA, said the agency would work with London Business School "to bring to life its new brand message".