In the early 19th century, a new Castle Lachlan was built for the chiefs of the clan, and it remains the seat of the clan to this day. The last of the male line chiefs of Clan Maclachlan was John Maclachlan who died in 1942. He was succeeded by his daughter, the twenty-fourth chief of the clan, Marjorie Maclachlan of Maclachlan. Under her the Clan Maclachlan Society was formed in 1979, and on her death in 1996, she was succeeded by her eldest son Euan John Maclachlan of Maclachlan, Chief of Clan Maclachlan, 25th of Maclachlan and Baron of Strathlachlan, who is a member of the Standing Council of Scottish Chiefs.

Today the clan is alive and lives as the Clan Maclachlan Society and the Lachlan Trust. The Clan Maclachlan Society consists of eight branches around the world, including Australia, Britain & Ireland, Canada, New Zealand, and the United States of America. The Lachlan Trust is a registered Scottish charitable organisation which takes donations to preserve the heritage of Clan Maclachlan. The trust, in part with Historic Scotland and the Heritage Lottery Fund, helped raise £100,000 for the preservation of Kilmorie Chapel, the traditional burying place of the chiefs. The project was completed in 2006, as a memorial to the twenty-fourth chief (the present chief's mother). Future projects may involve the preservation of old Castle Lachlan.