It is with great sadness and broken hearts that the family of Theo Olthof announce his peaceful passing at Hospice Niagara on September 8th at the age of 86 years. Beloved and devoted husband for 54 years of Elly. Cherished and loving Dad of Lisa (Jon Paul Miron), Pauline (Sukki Youn) and Stephanie (Jeff Gillbreath). Opa will be lovingly remembered by his grandchildren Megan and Kylie Miron, Ena and Gill Youn and Matthew Gillbreath. He will be very much missed by his sister and brother-in-law Gerda and John Northover and many other in-law family, nephews, nieces and friends in the Netherlands and Canada. Theo was one of nine children, born in Deventer, Netherlands to Theodorus Johannes Lebuinus Olthof and Henrika Maria Gerritsen. He is survived by 3 brothers and 3 sisters in the Netherlands and predeceased by 2 brothers. On July 15, 1955 on his 21st birthday, Theo bravely emigrated to Canada. After working a year out West, Theo studied at McGill University where he eventually graduated in 1962 with a PhD in Plant Pathology. He was employed by Agriculture Canada for over 30 years as a research scientist specializing in nematology. Theo was involved with Professional Institute of the Public Service of Canada as a member of the Executive for many years and was rewarded a life membership. Since his retirement, Theo enjoyed travelling with Elly to the Netherlands, Spain, Portugal and many other places. He loved all kinds of reading, especially in their beautiful backyard as well as the simple pleasures of life. We will miss Dad's witty sense of humour, warm smile and especially, his wise words of wisdom. Much appreciation to the staff at Hospice Niagara, Paramed nurses and LHIN Coordinator Pam, Dr. Levesque, Dr. Conen, Dr. Hyatt and staff. GEORGE DARTE FUNERAL HOME, 585 Carlton St. Catharines, will accept guests for visitation on Sunday, September 13th, from 2-4 p.m. and 7-9 p.m. with prayers at 3:45 p.m. A funeral mass will be held at 10:30 a.m. at the Cathedral of St. Catherine of Alexandria located at 3 Lyman St, St. Catharines, the following Monday, September the 14th. If desired, in lieu of flowers, contributions in Theo's memory can be made to Hospice Niagara, the Walker Family Cancer Centre, St. Vincent de Paul or a charity of your choice. On-Line Guest-Book at www.georgedartefuneralhome.com As per the Province of Ontario Covid-19 regulations, visitation attendance is limited to 30% the building capacity. Funeral attendance is limited to 66 guests. All guests must bring a mask.