Knight joins having previously worked for Silversea, Von Essen Hotels, NCL and Titan. His remit is the South of England and Northern Ireland.
Smithies will be based in the North and Scotland, having spent six years working for small ship specialist agency, Blue Water Holidays.
They join Jamie Loizou, sales, marketing and digital director, to complete the sales team.
Loizou said, “I am delighted that Jon and Jo, two people with such excellent and varied experience, have joined AmaWaterways.
“Our focus is to build strong partnerships and offer the best support to the UK travel trade, aiming to replicate the exceptional delivery that has seen our ships take the top 10 spots within the 2017 Berlitz River Cruising Guide.
“We have ambitious growth plans and through working closely with our trade partners, we want to see their businesses grow in tandem with ours.”