Theo Coster (born c. 1928) is an Israeli game designer and co-founder along with Ora Coster of Theora Concept Ltd., a family business which specializes in toys, games, crafts, and novelties.

Theo was born in 1928 in Amsterdam, near the North Sea. His family operated a printing business in Amsterdam.  A primary school classmate of Anne Frank, Theo walked to school with her often for several years before the Nazi’s came to Holland. When the Frank family went into hiding in Amsterdam, the Coster Family was hidden by a Christian family on a rural farm in The Netherlands. To avoid detection by the Gestapo, he was forced to change his given name, Maurice Simon, to Theo, a name he kept to this day. Theo survived, his friend, Anne, did not. 

Later, five of his surviving classmates helped him to produce a film "Classmates of Anne Frank" and book he wrote called, “we all wore stars” published in the United States and Great Britain by Palgrave-Macmillan. The book was also published by ten publishers in Australia, Brazil, Czech Rep. France, Germany, Holland, Italy, Japan, Portugal and Slovakia. It chronicles that time through his own experiences, those of his friends, and their memories of Anne. Theora Design is executive producer of the documentary film.

After running his family’s printing house in Amsterdam for three years, he took a motored bicycle journey over 3,000 miles to Turkey, from where he sailed to Israel and met Ora in 1955. They were married two years later. Despite childhoods branded by the scars of war, Ora and Theo Coster have succeeded in leaving an indelible mark of joy on generations of children the world over through imaginative play.

Since 1965, their company, Theora Design, founded in Tel Aviv, has created and licensed over 160 toy, game, craft and novelty concepts worldwide. In 1981 and 1993 respectively, Ora and Theo’s sons, Boaz and Gideon, joined the team, specializing in marketing and advanced technologies. Boaz’s wife Aliza Coster, (CPA) provides Theora with financial services.

Sadly we lost Theo in 2019.