The 46-year-old has been out of work since an ill-fated second spell in charge of Chelsea as interim boss for the final months of the 2022/23 season.
Coventry sit 17th in the English second tier and controversially sacked Mark Robins, who led them to the FA Cup semi-finals last season, earlier this month.
Lampard has signed a two-and-a-half-year contract and will take charge for the first time at home to Cardiff City on Saturday.
"I am delighted that Frank Lampard has agreed to join our club as head coach," said Coventry owner Doug King.
"Frank cut his teeth in the Championship and knows what is needed in this league to be successful.
"His experiences thereafter at Chelsea and Everton will ensure he brings to our talented squad clear understanding of exactly what is needed to succeed at the very top level that we as a club are striving to reach."
Chelsea's all-time leading goalscorer, Lampard has so far failed to match his glorious playing career since moving into management.
After an impressive one season at Derby County in the Championship, he was handed the Chelsea job for the first time in 2019.
However, he was sacked after 18 months with the Blues ninth in the Premier League and had to watch his successor Thomas Tuchel go on to win the Champions League later that season.
He was also dismissed after a year in charge of Everton in 2023.
Lampard returned to Stamford Bridge a few months later but managed just one win in 11 games as Chelsea finished 12th in the Premier League.
