Jonas Elmer (born 28 February 1988) is a Swiss footballer who currently works for FC Stäfa as a player-assistant coach.
Elmer was signed by English Premier League side Chelsea in the summer of 2005 from Grasshoppers.
Elmer made his first start for Chelsea's first team when coming on from the substitutes bench in a pre-season fixture against A.C. Milan, where he played the remainder of the match.
Elmer looked as though he could have a promising future at Chelsea and signed a new two-year contract in early April 2006.
He continued playing for his former youth club, FC Stäfa, in the Swiss 3rd division, as a player-assistant coach.