<?xml version="1.0" encoding="US-ASCII"?>
<!-- Generated by CompSci Transform (tm) - http://www.compsciresources.com -->
<!-- Created: Wed Apr 01 19:46:43 UTC 2026 -->
<linkbase xmlns="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" xmlns:xbrldt="http://xbrl.org/2005/xbrldt">
  <roleRef xlink:type="simple" xlink:href="trst-20260519.xsd#trst_r_AdditionalDimensions" roleURI="http://www.trustcobank.com/role/AdditionalDimensions"/>
  <arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default" arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default"/>
  <arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain" arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain"/>
  <arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension" arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension"/>
  <arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member" arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member"/>
  <arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all" arcroleURI="http://xbrl.org/int/dim/arcrole/all"/>
<!-- [WMV6][45t6Tw67GsuE7zMxQ9cAR/nK9utFw7Sq7KM6YO6go5+9zYyjKUc100Y1OBYxCv+eQwtRYOF1fZRcR/nzOJsMpN5BG2OHqVvha+MUOPbxFtYdRP8A/lKZ6tAVzh91IGmC/Qjb5zaSu1EqX6NghV52zfDYJy0iL/BgmfLnd3T8HQx2WvF4JBRGZaoAU0T8oivDoRlKcZEqfEoWxAvuQ74fEt2UAxesSRYZNxjO2L2dJ8/jufYveg1jqdsn2G4KbDHcw2F1Kx4iAmQoOdM5XGJF1gXjFQTtFLK8BLb3zre6x+5CdrLm6c6rTRRqmeUlwR0Q9dNEhP9G6iu9JrA0fguzeUrALePMbm5YcND5BGHSj7dzO5vBMEyrZzOaNA==] CSR-->
  <definitionLink xlink:role="http://www.trustcobank.com/role/AdditionalDimensions" xlink:type="extended"/>
</linkbase>
