Butler, who is Middle Temple Hall's sales and marketing manager, succeeds Angela Myles, who is moving to a venue outside of LCS's portfolio.
At LCS, Butler will work closely with other board members, and chair Diane Waldron.
Butler said: "I'm really excited to be leading the events strategy for the forthcoming year. The annual London City Selection fam trip is always a great success and I'm very much looking forward to leading on this. We already have some creative ideas and plans in the pipeline."
Waldron added: "We were delighted that Lorraine stepped up to the role of events chair. The annual fam trip is set to take place in March next year and with Lorraine's expertise and creative flair is set to be a great success."
Butler has previously worked at Parkstead House in Surrey and the Natural History Musuem.