Exhibit 99.1 City Office REIT Reports Fourth Quarter and Full Year 2023 Results VANCOUVER— February 22, 2024 —City Office REIT, Inc. (NYSE: CIO) (the “Company,” “City Office,” “we” or “our”) today announced its results for the quarter and full year ended December 31, 2023. Fourth Quarter Highlights • Rental and other revenues were $44.3 million. GAAP net loss attributable to common stockholders was approximately$4.5 million, or ($0.11) per fully diluted share; • Core FFO was approximately$13.5 million, or ...