Every two years, usually in August, the Society presents Theo Barker Memorial Lecture co-presented by Bathurst District Historical Society and Charles Sturt University. The first was held in 2007 with Pamela Freeman, Children's author, researcher and winner of the 2006 Young Peoples History Prize in the NSW Premier's History Awards. Her lecture was titled - "Distance, isolation, need. Mary MacKillop and rural life"

In 2009 the lecture was presented by Dr Peter Stanley and titled "The AIF's 'Bad Characters' - are we ready to know?"  Dr Peter Stanley is Director of the Centre for Historical Research at the National Museum of Australia. He is well known as a military and social historian.    

The third lecture in 2011 was by Assoc Professor Penny Russell from the University of Sydney and has many areas of historical research interest, including Colonial manners and etiquette. 

Lectures are held in memory of Theo Barker who became an active member of the Bathurst District Historical Society on his return to Bathurst in June 1955 when he took up an appointment as a teacher at the Bathurst Teacher's College.  Theo had a great gift for teaching and along with his love of his storytelling became a valued member of the society. From 1964 he was President of the society for a decade or more, again in 2000 – 2001 he was President. From 1956 to 2003 he served many of these years as part of the society's management committee before his death in August 2003.